{"id":14252,"date":"2025-06-07T10:49:49","date_gmt":"2025-06-07T03:49:49","guid":{"rendered":"https:\/\/www.ckconitsha.com\/vn\/?p=14252"},"modified":"2025-07-04T10:50:10","modified_gmt":"2025-07-04T03:50:10","slug":"tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3","status":"publish","type":"post","link":"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/","title":{"rendered":"T\u1ed5ng h\u1ee3p ki\u1ebfn th\u1ee9c v\u00e0 c\u00e1ch gi\u1ea3i b\u00e0i t\u1eadp d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_79_2 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Dau_hieu_chia_het_cho_3\" >D\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#So_nao_chia_het_cho_3\" >S\u1ed1 n\u00e0o chia h\u1ebft cho 3?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Dau_hieu_chia_het_cho_ca_3_va_9\" >D\u1ea5u hi\u1ec7u chia h\u1ebft cho c\u1ea3 3 v\u00e0 9<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Dau_hieu_chia_het_cho_3_cua_cac_so_tu_nhien_lien_tiep\" >D\u1ea5u hi\u1ec7u chia h\u1ebft cho 3 c\u1ee7a c\u00e1c s\u1ed1 t\u1ef1 nhi\u00ean li\u00ean ti\u1ebfp<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Dieu_kien_chia_het_cho_3_cua_mot_so\" >\u0110i\u1ec1u ki\u1ec7n chia h\u1ebft cho 3 c\u1ee7a m\u1ed9t s\u1ed1<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#0_co_chia_het_cho_3\" >0 c\u00f3 chia h\u1ebft cho 3?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Cac_tinh_chat_cua_dau_hieu_chia_het_cho_3\" >C\u00e1c t\u00ednh ch\u1ea5t c\u1ee7a d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Luu_y_va_sai_lam_thuong_gap_khi_su_dung_dau_hieu_chia_het_cho_3\" >L\u01b0u \u00fd v\u00e0 sai l\u1ea7m th\u01b0\u1eddng g\u1eb7p khi s\u1eed d\u1ee5ng d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Mot_so_loi_pho_bien_khi_lam_bai_tap_toan_chia_het_cho_3\" >M\u1ed9t s\u1ed1 l\u1ed7i ph\u1ed5 bi\u1ebfn khi l\u00e0m b\u00e0i t\u1eadp to\u00e1n chia h\u1ebft cho 3\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Luu_y_ve_so_am_va_so_0_trong_dau_hieu_chia_het_cho_3\" >L\u01b0u \u00fd v\u1ec1 s\u1ed1 \u00e2m v\u00e0 s\u1ed1 0 trong d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Bai_tap_dau_hieu_chia_het_cho_3\" >B\u00e0i t\u1eadp d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Bai_tap_trong_SGK_dap_an\" >B\u00e0i t\u1eadp trong SGK + \u0111\u00e1p \u00e1n<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Bai_tap_van_dung\" >B\u00e0i t\u1eadp v\u1eadn dung<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Bi_quyet_hoc_kien_thuc_Dau_hieu_chia_het_cho_3_hieu_qua\" >B\u00ed quy\u1ebft h\u1ecdc ki\u1ebfn th\u1ee9c D\u1ea5u hi\u1ec7u chia h\u1ebft cho 3 hi\u1ec7u qu\u1ea3<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.ckconitsha.com\/vn\/tong-hop-kien-thuc-va-cach-giai-bai-tap-dau-hieu-chia-het-cho-3\/#Ket_luan\" >K\u1ebft lu\u1eadn<\/a><\/li><\/ul><\/nav><\/div>\n<\/p>\n<p>Vi\u1ec7c nh\u1eadn bi\u1ebft \u0111\u01b0\u1ee3c d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3 s\u1ebd gi\u00fap c\u00e1c em gi\u1ea3i b\u00e0i t\u1eadp v\u00e0 t\u00ednh to\u00e1n nhanh ch\u00f3ng h\u01a1n. V\u1eady th\u1ebf n\u00e0o l\u00e0 s\u1ed1 chia h\u1ebft cho 3, \u0111\u1eb7c \u0111i\u1ec3m nh\u1eadn bi\u1ebft v\u00e0 c\u00e1ch gi\u1ea3i nh\u01b0 th\u1ebf n\u00e0o? H\u00e3y c\u00f9ng t\u00ecm hi\u1ec3u r\u00f5 h\u01a1n ngay trong b\u00e0i vi\u1ebft sau \u0111\u00e2y nh\u00e9.<\/p>\n<p>                        View all<\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Dau_hieu_chia_het_cho_3\"><\/span>D\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">D\u1ea5u hi\u1ec7u chia h\u1ebft cho 3 \u0111\u01b0\u1ee3c bi\u1ebft \u0111\u1ebfn l\u00e0 m\u1ed9t quy t\u1eafc \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c xem m\u1ed9t s\u1ed1 c\u00f3 chia h\u1ebft \u0111\u01b0\u1ee3c cho 3 hay kh\u00f4ng? C\u1ee5 th\u1ec3:<\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"So_nao_chia_het_cho_3\"><\/span>S\u1ed1 n\u00e0o chia h\u1ebft cho 3?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">\u0110\u1ec3 x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c s\u1ed1 n\u00e0o chia h\u1ebft cho 3, ta s\u1ebd d\u1ef1a v\u00e0o nh\u1eefng d\u1ea5u hi\u1ec7u sau:<\/p>\n<ul>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">T\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 chia h\u1ebft cho 3: M\u1ed9t s\u1ed1 chia h\u1ebft cho 3 l\u00e0 khi t\u1ed5ng nh\u1eefng ch\u1eef s\u1ed1 c\u1ee7a s\u1ed1 \u0111\u00f3 c\u0169ng s\u1ebd chia h\u1ebft cho 3.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">D\u1ea5u hi\u1ec7u t\u00ednh t\u1ed5ng \u0111\u1ed1i v\u1edbi s\u1ed1 l\u1edbn: N\u1ebfu m\u1ed9t d\u00e3y s\u1ed1 l\u1edbn kh\u00f4ng th\u1ec3 t\u00ednh t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 \u0111\u00f3, ta c\u00f3 th\u1ec3 l\u1ea5y s\u1ed1 \u0111\u00f3 chia l\u1ea5y s\u1ed1 d\u01b0 cho 3. N\u1ebfu k\u1ebft qu\u1ea3 v\u1edbi s\u1ed1 d\u01b0 b\u1eb1ng 0 th\u00ec s\u1ed1 \u0111\u00f3 s\u1ebd chia h\u1ebft cho 3 v\u00e0 ng\u01b0\u1ee3c l\u1ea1i.<\/p>\n<\/li>\n<\/ul>\n<p dir=\"ltr\"><\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Dau_hieu_chia_het_cho_ca_3_va_9\"><\/span>D\u1ea5u hi\u1ec7u chia h\u1ebft cho c\u1ea3 3 v\u00e0 9<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">\u0110\u1ed1i v\u1edbi nh\u1eefng s\u1ed1 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 chia h\u1ebft cho 9 s\u1ebd chia h\u1ebft \u0111\u01b0\u1ee3c cho c\u1ea3 3 v\u00e0 9.<\/p>\n<p dir=\"ltr\"><em>V\u00ed d\u1ee5:<\/em><\/p>\n<p dir=\"ltr\"><em>S\u1ed1 189 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 1 + 8 + 9 = 18 chi h\u1ebft \u0111\u01b0\u1ee3c cho 9, l\u00fac n\u00e0y 189 c\u0169ng s\u1ebd chia h\u1ebft \u0111\u01b0\u1ee3c cho 3.\u00a0\u00a0<\/em><\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Dau_hieu_chia_het_cho_3_cua_cac_so_tu_nhien_lien_tiep\"><\/span>D\u1ea5u hi\u1ec7u chia h\u1ebft cho 3 c\u1ee7a c\u00e1c s\u1ed1 t\u1ef1 nhi\u00ean li\u00ean ti\u1ebfp<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">V\u1edbi c\u00e1c s\u1ed1 t\u1ef1 nhi\u00ean li\u00ean ti\u1ebfp, m\u1ecdi ng\u01b0\u1eddi c\u00f3 th\u1ec3 nh\u1eadn bi\u1ebft s\u1ed1 \u0111\u00f3 c\u00f3 chia h\u1ebft \u0111\u01b0\u1ee3c cho 3 hay kh\u00f4ng d\u1ef1a v\u00e0o t\u00ednh ch\u1ea5t c\u1ee7a d\u00e3y s\u1ed1 \u0111\u00f3. C\u1ee5 th\u1ec3:<\/p>\n<ul>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Li\u00ean ti\u1ebfp 3 s\u1ed1 chia h\u1ebft cho 3: Tr\u01b0\u1eddng h\u1ee3p 3 s\u1ed1 t\u1ef1 nhi\u00ean li\u00ean ti\u1ebfp, ch\u1eb5n l\u1ebb l\u1eabn nhau \u0111\u1ec1u c\u00f3 th\u1ec3 chia h\u1ebft cho 3. V\u00ed d\u1ee5: 8, 9, 10 \u0111\u1ec1u chia h\u1ebft cho 3.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Li\u00ean ti\u1ebfp 2 s\u1ed1 chia h\u1ebft cho 3: Tr\u01b0\u1eddng h\u1ee3p 2 s\u1ed1 t\u1ef1 nhi\u00ean li\u00ean ti\u1ebfp nhau c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 chia h\u1ebft cho 3 th\u00ec c\u1ea3 hai s\u1ed1 \u0111\u00f3 \u0111\u1ec1u chia h\u1ebft cho 3. V\u00ed d\u1ee5: 6 v\u00e0 9 (6 + 9 = 15) \u0111\u1ec1u chia h\u1ebft cho 3.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Li\u00ean ti\u1ebfp 4 s\u1ed1 chia h\u1ebft cho 3: Tr\u01b0\u1eddng h\u1ee3p 4 s\u1ed1 t\u1ef1 nhi\u00ean li\u00ean ti\u1ebfp c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 chia h\u1ebft cho 4 th\u00ec c\u00e1c s\u1ed1 \u0111\u00f3 \u0111\u1ec1u chia h\u1ebft cho 3. V\u00ed d\u1ee5: 5, 6, 7, 8 (5 + 6 + 7 + 8 = 26) \u0111\u1ec1u chia h\u1ebft cho 3.<\/p>\n<\/li>\n<\/ul>\n<p dir=\"ltr\">C\u0169ng t\u01b0\u01a1ng t\u1ef1 v\u1edbi c\u00e1c d\u00e3y li\u00ean ti\u1ebfp 5, 6, 7\u2026 s\u1ed1 t\u1ef1 nhi\u00ean kh\u00e1c c\u0169ng c\u00f3 th\u1ec3 \u00e1p d\u1ee5ng quy t\u1eafc n\u00e0y \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3.<\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Dieu_kien_chia_het_cho_3_cua_mot_so\"><\/span>\u0110i\u1ec1u ki\u1ec7n chia h\u1ebft cho 3 c\u1ee7a m\u1ed9t s\u1ed1<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">\u0110i\u1ec1u ki\u1ec7n \u0111\u1ec3 m\u1ed9t s\u1ed1 nguy\u00ean chia h\u1ebft cho 3 ch\u00ednh l\u00e0 khi s\u1ed1 \u0111\u00f3 chia h\u1ebft cho 3 v\u00e0 kh\u00f4ng d\u01b0.<\/p>\n<p dir=\"ltr\" style=\"text-align: center\">Cho s\u1ed1 nguy\u00ean a, n\u1ebfu a chia h\u1ebft cho 3, ta c\u00f3: a % 3 = 0<\/p>\n<p dir=\"ltr\">Trong \u0111\u00f3, &#8220;%&#8221; l\u00e0 k\u00fd hi\u1ec7u to\u00e1n h\u1ecdc d\u00f9ng \u0111\u1ec3 bi\u1ec3u th\u1ecb ph\u00e9p chia l\u1ea5y s\u1ed1 d\u01b0. N\u1ebfu k\u1ebft qu\u1ea3 ph\u00e9p chia c\u1ee7a a cho 3 l\u00e0 0, t\u1ee9c l\u00e0 kh\u00f4ng c\u00f2n d\u01b0, th\u00ec a chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\"><em>V\u00ed d\u1ee5:<\/em><\/p>\n<p dir=\"ltr\"><em>S\u1ed1 9 chia h\u1ebft cho 3 v\u00ec 9 % 3 = 0.<\/em><\/p>\n<p dir=\"ltr\"><em>S\u1ed1 16 kh\u00f4ng chia h\u1ebft cho 3 v\u00ec 16 % 3 = 1 (c\u00f3 d\u01b0 1).<\/em><\/p>\n<p dir=\"ltr\"><em>S\u1ed1 27 chia h\u1ebft cho 3 v\u00ec 27 % 3 = 0.<\/em><\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"0_co_chia_het_cho_3\"><\/span>0 c\u00f3 chia h\u1ebft cho 3?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">Trong to\u00e1n h\u1ecdc, 0 l\u00e0 m\u1ed9t s\u1ed1 chia h\u1ebft \u0111\u01b0\u1ee3c cho m\u1ecdi s\u1ed1 kh\u00e1c kh\u00f4ng hay m\u1ecdi s\u1ed1 nguy\u00ean \u0111\u1ec1u chia h\u1ebft cho 1 v\u00e0 m\u1ed7i s\u1ed1 nguy\u00ean kh\u00e1c 0 \u0111\u1ec1u c\u00f3 th\u1ec3 chia h\u1ebft \u0111\u01b0\u1ee3c cho ch\u00ednh n\u00f3. V\u1eady n\u00ean, 0 c\u00f3 chia h\u1ebft \u0111\u01b0\u1ee3c cho 3.<\/p>\n<table style=\"border-collapse: collapse;width: 100%;background-color: #fbeeb8\" border=\"1\">\n<tr>\n<td style=\"width: 98.5189%\">\n<p style=\"text-align: center\">GI\u00daP CON H\u1eccC TO\u00c1N K\u1ebeT H\u1ee2P V\u1edaI TI\u1ebeNG ANH SI\u00caU TI\u1ebeT KI\u1ec6M CH\u1ec8 TR\u00caN M\u1ed8T APP MONKEY MATH. V\u1edaI N\u1ed8I DUNG D\u1ea0Y H\u1eccC \u0110A PH\u01af\u01a0NG PH\u00c1P GI\u00daP B\u00c9 PH\u00c1T TRI\u1ec2N T\u01af DUY N\u00c3O B\u1ed8 V\u00c0 NG\u00d4N NG\u1eee TO\u00c0N DI\u1ec6N CH\u1ec8 V\u1edaI KHO\u1ea2NG 2K\/NG\u00c0Y.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" style=\"margin-left: auto;margin-right: auto\" class=\"lazyload\" src=\"https:\/\/external-content.duckduckgo.com\/iu\/?u=https:\/\/vnmedia2.monkeyuni.net\/upload\/web\/img\/timhieungay.png\" alt=\"\" width=\"200\" height=\"41\"><\/p>\n<\/td>\n<\/tr>\n<\/table>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Cac_tinh_chat_cua_dau_hieu_chia_het_cho_3\"><\/span>C\u00e1c t\u00ednh ch\u1ea5t c\u1ee7a d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">N\u1ebfu m\u1ed9t s\u1ed1 chia h\u1ebft cho 3 s\u1ebd bao g\u1ed3m nh\u1eefng \u0111\u1eb7c \u0111i\u1ec3m t\u00ednh ch\u1ea5t sau:<\/p>\n<ul>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">N\u1ebfu m\u1ed9t s\u1ed1 chia h\u1ebft cho 3 c\u00f3 th\u1ec3 l\u00e0 s\u1ed1 l\u1ebb ho\u1eb7c s\u1ed1 ch\u1eb5n.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">S\u1ed1 chia h\u1ebft cho 3 ch\u01b0a ch\u1eafc chia h\u1ebft \u0111\u01b0\u1ee3c cho 6, 9, 12\u2026 nh\u01b0ng m\u1ed9t s\u1ed1 chia h\u1ebft cho 6, 9, 12\u2026 l\u1ea1i chia h\u1ebft \u0111\u01b0\u1ee3c cho 3.<\/p>\n<\/li>\n<\/ul>\n<p dir=\"ltr\"><em>V\u00ed d\u1ee5: Ch\u1ee9ng minh r\u1eb1ng s\u1ed1 1890 chia h\u1ebft cho 3.<\/em><\/p>\n<p dir=\"ltr\"><em>Gi\u1ea3i: G\u1ecdi N l\u00e0 t\u1eadp h\u1ee3p c\u00e1c ph\u1ea7n t\u1eed c\u1ee7a s\u1ed1 1890.<\/em><\/p>\n<p dir=\"ltr\"><em>N = {1;8;9;0}<\/em><\/p>\n<p dir=\"ltr\"><em>T\u1ed5ng c\u1ee7a c\u00e1c ph\u1ea7n t\u1eed trong N l\u00e0: 1 + 8 + 9 + 0 = 18. L\u00fac n\u00e0y ta th\u1ea5y 18 chia h\u1ebft cho 3 n\u00ean s\u1ed1 1890 chia h\u1ebft cho 3.<\/em><\/p>\n<p dir=\"ltr\"><img decoding=\"async\" class=\"lazyload\" src=\"https:\/\/external-content.duckduckgo.com\/iu\/?u=https:\/\/vnmedia2.monkeyuni.net\/upload\/web\/img\/dau-hieu-chia-het-cho-3-2.png\" alt=\"M\u1ed9t s\u1ed1 t\u00ednh ch\u1ea5t quan tr\u1ecdng trong d\u1ea5u hi\u1ec7u chia h\u1ebft c\u1ea7n n\u1eafm r\u00f5. (\u1ea2nh: S\u01b0u t\u1ea7m internet)\" width=\"100%\"><\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Luu_y_va_sai_lam_thuong_gap_khi_su_dung_dau_hieu_chia_het_cho_3\"><\/span>L\u01b0u \u00fd v\u00e0 sai l\u1ea7m th\u01b0\u1eddng g\u1eb7p khi s\u1eed d\u1ee5ng d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">Trong qu\u00e1 tr\u00ecnh gi\u1ea3i b\u00e0i t\u1eadp v\u1ec1 d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3, c\u00e1c em c\u1ea7n l\u01b0u \u00fd m\u1ed9t s\u1ed1 v\u1ea5n \u0111\u1ec1 sau:<\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Mot_so_loi_pho_bien_khi_lam_bai_tap_toan_chia_het_cho_3\"><\/span>M\u1ed9t s\u1ed1 l\u1ed7i ph\u1ed5 bi\u1ebfn khi l\u00e0m b\u00e0i t\u1eadp to\u00e1n chia h\u1ebft cho 3\u00a0<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">L\u1ed7i t\u00ednh to\u00e1n sai: \u0110\u00e2y l\u00e0 l\u1ed7i th\u01b0\u1eddng g\u1eb7p khi th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh chia ho\u1eb7c chia l\u1ea5y s\u1ed1 d\u01b0. V\u1eady n\u00ean, h\u00e3y ki\u1ec3m tra l\u1ea1i c\u00e1c b\u01b0\u1edbc t\u00ednh to\u00e1n \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o b\u00e9 gi\u1ea3i \u0111\u00fang ph\u00e9p t\u00ednh, v\u00ec ch\u1ec9 sai m\u1ed9t s\u1ed1 ho\u1eb7c d\u1ea5u c\u0169ng s\u1ebd sai k\u1ebft qu\u1ea3.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Kh\u00f4ng ki\u1ec3m tra c\u1ea9n th\u1eadn: Khi gi\u1ea3i to\u00e1n s\u1ed1 chia h\u1ebft cho 3, nhi\u1ec1u b\u00e9 kh\u00f4ng ki\u1ec3m tra c\u1ea9n th\u1eadn k\u1ebft qu\u1ea3 c\u1ee7a ph\u00e9p chia l\u1ea5y s\u1ed1 d\u01b0, n\u00ean d\u1ec5 b\u1ecf s\u00f3t tr\u01b0\u1eddng h\u1ee3p m\u00e0 s\u1ed1 d\u01b0 l\u00e0 0 n\u00ean d\u1eabn t\u1edbi vi\u1ec7c k\u1ebft lu\u1eadn s\u1ed1 \u0111\u00f3 chia h\u1ebft cho 3 hay kh\u00f4ng c\u0169ng b\u1ecb sai.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">L\u00e0m tr\u00f2n sai: Khi gi\u1ea3i to\u00e1n chia l\u1ea5y s\u1ed1 d\u01b0, m\u1ed9t s\u1ed1 b\u00e9 th\u01b0\u1eddng l\u00e0m tr\u00f2n sai k\u1ebft qu\u1ea3. N\u00ean h\u00e3y l\u00e0m tr\u00f2n \u0111\u1ebfn \u0111\u00fang ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n n\u1ebfu c\u1ea7n thi\u1ebft.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Kh\u00f4ng x\u00e9t t\u1edbi s\u1ed1 \u00e2m: \u0110a ph\u1ea7n c\u00e1c b\u00e9 khi ki\u1ec3m tra s\u1ed1 c\u00f3 chia h\u1ebft cho 3 kh\u00f4ng ch\u1ec9 x\u00e9t s\u1ed1 d\u01b0\u01a1ng. Nh\u01b0ng nhi\u1ec1u b\u00e0i t\u1eadp c\u00f2n c\u00f3 c\u1ea3 s\u1ed1 \u00e2m, n\u00ean n\u1ebfu m\u1ed9t s\u1ed1 \u00e2m chia h\u1ebft cho 3, th\u00ec s\u1ed1 t\u01b0\u01a1ng \u1ee9ng d\u01b0\u01a1ng c\u0169ng chia h\u1ebft cho 3.<\/p>\n<\/li>\n<\/ul>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Luu_y_ve_so_am_va_so_0_trong_dau_hieu_chia_het_cho_3\"><\/span>L\u01b0u \u00fd v\u1ec1 s\u1ed1 \u00e2m v\u00e0 s\u1ed1 0 trong d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li dir=\"ltr\">S\u1ed1 \u00e2m chia h\u1ebft cho 3: N\u1ebfu m\u1ed9t s\u1ed1 \u00e2m chia h\u1ebft cho 3 th\u00ec s\u1ed1 d\u01b0\u01a1ng t\u01b0\u01a1ng \u1ee9ng \u0111\u00f3 c\u0169ng chia h\u1ebft cho 3. Ch\u1eb3ng h\u1ea1n, &#8211; 9 chia h\u1ebft cho 3 v\u00ec 9 chia h\u1ebft cho 3.<\/li>\n<li dir=\"ltr\">S\u1ed1 0 chia h\u1ebft cho 3: S\u1ed1 0 l\u00e0 m\u1ed9t s\u1ed1 chia h\u1ebft \u0111\u01b0\u1ee3c cho 3 v\u00ec n\u00f3 kh\u00f4ng d\u01b0 khi chia cho b\u1ea5t k\u1ef3 s\u1ed1 nguy\u00ean d\u01b0\u01a1ng n\u00e0o.\u00a0\u00a0<\/li>\n<\/ul>\n<p dir=\"ltr\"><em>V\u00ed d\u1ee5:<\/em><\/p>\n<p dir=\"ltr\"><em>S\u1ed1 -9 chia h\u1ebft cho 3 v\u00ec -9 % 3 = 0.<\/em><\/p>\n<p dir=\"ltr\"><em>S\u1ed1 0 chia h\u1ebft cho 3 v\u00ec 0 % 3 = 0.<\/em><\/p>\n<p dir=\"ltr\"><em>S\u1ed1 -15 chia h\u1ebft cho 3 v\u00ec -15 % 3 = 0.<\/em><\/p>\n<p dir=\"ltr\"><em>S\u1ed1 12 chia h\u1ebft cho 3 v\u00ec 12 % 3 = 0.<\/em><\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Bai_tap_dau_hieu_chia_het_cho_3\"><\/span>B\u00e0i t\u1eadp d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">\u0110\u1ec3 gi\u00fap c\u00e1c em hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 ki\u1ebfn th\u1ee9c d\u1ea5u hi\u1ec7u m\u1ed9t s\u1ed1 chia h\u1ebft cho 3, d\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 b\u00e0i t\u1eadp m\u00e0 Shining Home &#8211; Gia \u0111\u00ecnh Anh Ng\u1eef t\u1ed5ng h\u1ee3p \u0111\u1ec3 b\u00e9 tham kh\u1ea3o v\u00e0 th\u1ef1c h\u00e0nh.<\/p>\n<p dir=\"ltr\"><img decoding=\"async\" class=\"lazyload\" src=\"https:\/\/external-content.duckduckgo.com\/iu\/?u=https:\/\/vnmedia2.monkeyuni.net\/upload\/web\/img\/dau-hieu-chia-het-cho-3-3.png\" alt=\"Gi\u1ea3i b\u00e0i t\u1eadp th\u01b0\u1eddng xuy\u00ean s\u1ebd gi\u00fap n\u00e2ng cao hi\u1ec7u qu\u1ea3 t\u00ednh to\u00e1n. (\u1ea2nh: S\u01b0u t\u1ea7m internet)\" width=\"100%\"><\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Bai_tap_trong_SGK_dap_an\"><\/span>B\u00e0i t\u1eadp trong SGK + \u0111\u00e1p \u00e1n<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">To\u00e1n l\u1edbp 4 trang 98 B\u00e0i 1<\/p>\n<p dir=\"ltr\">Trong c\u00e1c s\u1ed1 sau, s\u1ed1 n\u00e0o chia h\u1ebft cho 3?<\/p>\n<p dir=\"ltr\">231; 109; 1872; 8225; 92 313.<\/p>\n<p dir=\"ltr\">\u0110\u00e1p \u00e1n:<\/p>\n<p dir=\"ltr\">+) S\u1ed1 231 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 2 + 3 + 1 = 6.<\/p>\n<p dir=\"ltr\">M\u00e0 6 chia h\u1ebft cho 3 n\u00ean s\u1ed1 231 chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">+) S\u1ed1 109 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 1 + 0 + 9 = 10 .<\/p>\n<p dir=\"ltr\">M\u00e0 10 kh\u00f4ng chia h\u1ebft cho 3 n\u00ean s\u1ed1 109 kh\u00f4ng chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">+) S\u1ed1 1872 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 1 + 8 + 7 + 2 = 18.<\/p>\n<p dir=\"ltr\">M\u00e0 18 chia h\u1ebft cho 3 n\u00ean s\u1ed1 1872 chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">+) S\u1ed1 8225 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 8 + 2 + 2 + 5 = 17.<\/p>\n<p dir=\"ltr\">M\u00e0 17 kh\u00f4ng chia h\u1ebft cho 3 n\u00ean s\u1ed1 8225 kh\u00f4ng chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">+) S\u1ed1 92 313 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 9 + 2 + 3 + 1 + 3 = 18.<\/p>\n<p dir=\"ltr\">M\u00e0 18 chia h\u1ebft cho 3 n\u00ean s\u1ed1 92 313 chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">V\u1eady trong c\u00e1c s\u1ed1 \u0111\u00e3 cho, c\u00e1c s\u1ed1 chia h\u1ebft cho 3 l\u00e0:<\/p>\n<p dir=\"ltr\">231 ; 1872 ; 92 313.<\/p>\n<p dir=\"ltr\">To\u00e1n l\u1edbp 4 trang 98 B\u00e0i 2<\/p>\n<p dir=\"ltr\">Trong c\u00e1c s\u1ed1 sau, s\u1ed1 n\u00e0o kh\u00f4ng chia h\u1ebft cho 3?<\/p>\n<p dir=\"ltr\">96; 502; 6823; 55 553; 641 311.<\/p>\n<p dir=\"ltr\">\u0110\u00e1p \u00e1n:<\/p>\n<p dir=\"ltr\">+) S\u1ed1 96 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 9 + 6 = 15.<\/p>\n<p dir=\"ltr\">M\u00e0 15 chia h\u1ebft cho 3 n\u00ean s\u1ed1 96 chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">+) S\u1ed1 502 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 5 + 0 + 2 = 7.<\/p>\n<p dir=\"ltr\">M\u00e0 7 kh\u00f4ng chia h\u1ebft cho 3 n\u00ean s\u1ed1 502 kh\u00f4ng chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">+) S\u1ed1 6823 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 6 + 8 + 2 + 3 = 19.<\/p>\n<p dir=\"ltr\">M\u00e0 19 kh\u00f4ng chia h\u1ebft cho 3 n\u00ean s\u1ed1 6823 kh\u00f4ng chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">+) S\u1ed1 55 553 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 5 + 5 + 5 + 5 + 3 = 23.<\/p>\n<p dir=\"ltr\">M\u00e0 23 kh\u00f4ng chia h\u1ebft cho 3 n\u00ean s\u1ed1 55 553 kh\u00f4ng chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">+) S\u1ed1 641 311 c\u00f3 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 l\u00e0 6 + 4 + 1 + 3 + 1 + 1 = 16.<\/p>\n<p dir=\"ltr\">M\u00e0 16 kh\u00f4ng chia h\u1ebft cho 3 n\u00ean s\u1ed1 641 311 kh\u00f4ng chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">V\u1eady trong c\u00e1c s\u1ed1 \u0111\u00e3 cho, c\u00e1c s\u1ed1 kh\u00f4ng chia h\u1ebft cho 3 l\u00e0 :<\/p>\n<p dir=\"ltr\">502; 6823; 55553; 641311<\/p>\n<p dir=\"ltr\">To\u00e1n l\u1edbp 4 trang 98 B\u00e0i 3<\/p>\n<p dir=\"ltr\">Vi\u1ebft ba s\u1ed1 c\u00f3 ba ch\u1eef s\u1ed1 v\u00e0 chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">\u0110\u00e1p \u00e1n:<\/p>\n<p dir=\"ltr\">C\u00e1c em c\u00f3 th\u1ec3 vi\u1ebft c\u00e1c s\u1ed1 nh\u01b0: 351; 648; 891.<\/p>\n<p dir=\"ltr\">Gi\u1ea3i To\u00e1n l\u1edbp 4 trang 98 B\u00e0i 4<\/p>\n<p dir=\"ltr\">T\u00ecm ch\u1eef s\u1ed1 th\u00edch h\u1ee3p vi\u1ebft v\u00e0o \u00f4 tr\u1ed1ng \u0111\u1ec3 \u0111\u01b0\u1ee3c c\u00e1c s\u1ed1 chia h\u1ebft cho 3 nh\u01b0ng kh\u00f4ng chia h\u1ebft cho 9 : 56\u2026; 79\u2026; 2\u202635.<\/p>\n<p dir=\"ltr\">L\u1eddi gi\u1ea3i:<\/p>\n<p dir=\"ltr\">+) \u0110\u1ec3 56\u2026 chia h\u1ebft cho 3 th\u00ec 5 + 6 + \u2026 = 11 + \u2026 chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">S\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o ch\u1ed7 ch\u1ea5m l\u00e0: 1 ho\u1eb7c 4<\/p>\n<p dir=\"ltr\">Ta \u0111\u01b0\u1ee3c c\u00e1c s\u1ed1: 561 ho\u1eb7c 564 ho\u1eb7c 567 (lo\u1ea1i 567 v\u00ec 567 chia h\u1ebft cho 9)<\/p>\n<p dir=\"ltr\">V\u1eady c\u00e1c s\u1ed1 chia h\u1ebft cho 3 m\u00e0 kh\u00f4ng chia h\u1ebft cho 9 l\u00e0 561 ho\u1eb7c 564.\u00a0<\/p>\n<p dir=\"ltr\">+) \u0110\u1ec3 79\u2026 chia h\u1ebft cho 3 th\u00ec 7 + 9 + \u2026 = 16 + \u2026 chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">S\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o ch\u1ed7 ch\u1ea5m l\u00e0: 2 ho\u1eb7c 5 ho\u1eb7c 8\u00a0<\/p>\n<p dir=\"ltr\">Ta \u0111\u01b0\u1ee3c c\u00e1c s\u1ed1: 792 ho\u1eb7c 795 ho\u1eb7c 798 (lo\u1ea1i 792 v\u00ec 792 chia h\u1ebft cho 9)<\/p>\n<p dir=\"ltr\">V\u1eady c\u00e1c s\u1ed1 chia h\u1ebft cho 3 m\u00e0 kh\u00f4ng chia h\u1ebft cho 9 l\u00e0 795 ho\u1eb7c 798.<\/p>\n<p dir=\"ltr\">+) \u0110\u1ec3 2\u202635 chia h\u1ebft cho 3 th\u00ec 2 + \u2026 + 3 + 5 = 10 + \u2026 chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">S\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o ch\u1ed7 ch\u1ea5m l\u00e0: 2 ho\u1eb7c 5 ho\u1eb7c 8<\/p>\n<p dir=\"ltr\">Ta \u0111\u01b0\u1ee3c c\u00e1c s\u1ed1: 2235; 2535; 2835 (lo\u1ea1i 2835 v\u00ec 2835 chia h\u1ebft cho 9)<\/p>\n<p dir=\"ltr\">V\u1eady c\u00e1c s\u1ed1 chia h\u1ebft cho 3 m\u00e0 kh\u00f4ng chia h\u1ebft cho 9 l\u00e0 2235 v\u00e0 2535.<\/p>\n<h3 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Bai_tap_van_dung\"><\/span>B\u00e0i t\u1eadp v\u1eadn dung<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p dir=\"ltr\">C\u00e2u 1: Cho 5 s\u1ed1 0;1;3;6;7. C\u00f3 bao nhi\u00eau s\u1ed1 t\u1ef1 nhi\u00ean c\u00f3 ba ch\u1eef s\u1ed1 v\u00e0 chia h\u1ebft cho 3 \u0111\u01b0\u1ee3c l\u1eadp t\u1eeb c\u00e1c s\u1ed1 tr\u00ean m\u00e0 c\u00e1c ch\u1eef s\u1ed1 kh\u00f4ng l\u1eadp l\u1ea1i.<\/p>\n<p dir=\"ltr\">C\u00e2u 2: Ch\u1ee9ng minh r\u1eb1ng t\u00edch c\u1ee7a 3 s\u1ed1 t\u1ef1 nhi\u00ean li\u00ean ti\u1ebfp lu\u00f4n chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">C\u00e2u 3: T\u1eeb 4 ch\u1eef s\u1ed1 3; 4; 5; 0. H\u00e3y gh\u00e9p th\u00e0nh c\u00e1c s\u1ed1 t\u1ef1 nhi\u00ean c\u00f3 3 ch\u1eef s\u1ed1 kh\u00e1c nhau th\u1ecfa m\u00e3n:<\/p>\n<p dir=\"ltr\">a) Chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">b) Chia h\u1ebft cho 3 nh\u01b0ng kh\u00f4ng chia h\u1ebft cho 9.<\/p>\n<p dir=\"ltr\">C\u00e2u 4: Cho s\u1ed1 3*46. H\u00e3y thay d\u1ea5u * b\u1eb1ng ch\u1eef s\u1ed1 \u0111\u1ec3 \u0111\u01b0\u1ee3c s\u1ed1 chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">C\u00e2u 5:\u00a0 Trong c\u00e1c s\u1ed1 156; 2018; 2505; 11 200; 781:<\/p>\n<p dir=\"ltr\">a) S\u1ed1 n\u00e0o chia h\u1ebft cho 3?<\/p>\n<p dir=\"ltr\">b) S\u1ed1 n\u00e0o kh\u00f4ng chia h\u1ebft cho 3?<\/p>\n<p dir=\"ltr\">\u00a0C\u00e2u 6: T\u00ecm X, bi\u1ebft : X chia h\u1ebft cho 3 v\u00e0 360 &lt; X &lt; 370;<\/p>\n<p dir=\"ltr\">C\u00e2u 7:Kh\u00f4ng l\u00e0m ph\u00e9p t\u00ednh, h\u00e3y x\u00e9t xem c\u00e1c t\u1ed5ng v\u00e0 hi\u1ec7u d\u01b0\u1edbi \u0111\u00e2y c\u00f3 chia h\u1ebft cho 3 hay kh\u00f4ng?<\/p>\n<p dir=\"ltr\">240 + 123 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 240 &#8211; 123<\/p>\n<p dir=\"ltr\">2454 + 374 + 135\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 2454 &#8211; 374 &#8211; 135<\/p>\n<p dir=\"ltr\">C\u00e2u 8: L\u1edbp 4A c\u00f3 h\u01a1n 30 h\u1ecdc sinh nh\u01b0ng s\u0129 s\u1ed1 kh\u00f4ng qu\u00e1 40 m\u00e0 x\u1ebfp h\u00e0ng \u0111\u00f4i v\u00e0o l\u1edbp th\u00ec hai h\u00e0ng b\u1eb1ng nhau v\u00e0 chia l\u00e0m 3 t\u1ed5 th\u00ec c\u00f3 s\u1ed1 h\u1ecdc sinh b\u1eb1ng nhau.\u00a0<\/p>\n<p dir=\"ltr\">C\u00e2u 9: Cho c\u00e1c s\u1ed1: 3564; 4352; 6531; 6570; 1248.<\/p>\n<p dir=\"ltr\">a) Vi\u1ebft t\u1eadp h\u1ee3p A c\u00e1c s\u1ed1 chia h\u1ebft cho 3 trong c\u00e1c s\u1ed1 tr\u00ean.<\/p>\n<p dir=\"ltr\">b) Vi\u1ebft t\u1eadp h\u1ee3p B c\u00e1c s\u1ed1 chia h\u1ebft cho 9 trong c\u00e1c s\u1ed1 tr\u00ean.<\/p>\n<p dir=\"ltr\">c) D\u00f9ng k\u00ed hi\u1ec7u \u2282 \u0111\u1ec3 th\u1ec3 hi\u1ec7n quan h\u1ec7 gi\u1eefa hai t\u1eadp h\u1ee3p A v\u00e0 B.<\/p>\n<p dir=\"ltr\">C\u00e2u 10: T\u00ecm ch\u1eef s\u1ed1 y \u0111\u1ec3 s\u1ed1 58y91 chia h\u1ebft cho 3 v\u00e0 t\u1ed5ng c\u00e1c ch\u1eef s\u1ed1 c\u1ee7a s\u1ed1 58y91 nh\u1ecf h\u01a1n 25.<\/p>\n<p dir=\"ltr\">C\u00e2u 11: T\u00ecm s\u1ed1 t\u1ef1 nhi\u00ean x bi\u1ebft 921&lt;x&lt;925 v\u00e0 x chia h\u1ebft cho 3.<\/p>\n<p dir=\"ltr\">C\u00e2u 12: S\u1ed1 853471 chia cho 3 d\u01b0 m\u1ea5y?<\/p>\n<p dir=\"ltr\">C\u00e2u 13: S\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 2 ch\u1eef s\u1ed1 chia cho 2, cho 3 v\u00e0 cho 5 \u0111\u1ec1u d\u01b0 1 l\u00e0 bao nhi\u00eau?<\/p>\n<p dir=\"ltr\">C\u00e2u 14:\u00a0 Vi\u1ebft ti\u1ebfp v\u00e0o ch\u1ed7 ch\u1ea5m:<\/p>\n<p dir=\"ltr\">Trong c\u00e1c s\u1ed1 96; 502; 6823; 55 553; 641 311, s\u1ed1 kh\u00f4ng chia h\u1ebft cho 3 l\u00e0: &#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;..<\/p>\n<p dir=\"ltr\">&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p dir=\"ltr\">3. a) VI\u1ebft hai s\u1ed1 c\u00f3 b\u1ed1n ch\u1eef s\u1ed1 v\u00e0 chia h\u1ebft cho 3: &#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;..<\/p>\n<p dir=\"ltr\">b) Vi\u1ebft ba s\u1ed1 l\u1ebb c\u00f3 ba ch\u1eef s\u1ed1 v\u00e0 chia h\u1ebft cho 9: &#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;..<\/p>\n<p dir=\"ltr\">C\u00e2u 15:\u00a0 \u0110\u00fang ghi \u0110, sai ghi S:<\/p>\n<p dir=\"ltr\">T\u00ecm ch\u1eef s\u1ed1 th\u00edch h\u1ee3p vi\u1ebft v\u00e0o \u00f4 tr\u1ed1ng sao cho: 9 &#8230;&#8230;.. 24 chia h\u1ebft cho 3 nh\u01b0ng kh\u00f4ng chia h\u1ebft cho 9<\/p>\n<p dir=\"ltr\">Ch\u1eef s\u1ed1 th\u00edch h\u1ee3p \u0111\u00f3 l\u00e0:\u00a0<\/p>\n<table style=\"border-collapse: collapse;width: 100%\">\n<tr>\n<td>\n<p dir=\"ltr\">a) 9 &#8230;&#8230;..<\/p>\n<\/td>\n<td>\n<p dir=\"ltr\">b) 6 &#8230;&#8230;..<\/p>\n<\/td>\n<td>\n<p dir=\"ltr\">c) 3 &#8230;&#8230;..<\/p>\n<\/td>\n<td>\n<p dir=\"ltr\">d) 0 &#8230;&#8230;..<\/p>\n<\/td>\n<\/tr>\n<\/table>\n<p dir=\"ltr\">\u00a0<\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Bi_quyet_hoc_kien_thuc_Dau_hieu_chia_het_cho_3_hieu_qua\"><\/span>B\u00ed quy\u1ebft h\u1ecdc ki\u1ebfn th\u1ee9c D\u1ea5u hi\u1ec7u chia h\u1ebft cho 3 hi\u1ec7u qu\u1ea3<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">\u0110\u1ec3 gi\u00fap c\u00e1c b\u00e9 h\u1ecdc hi\u1ec3u ki\u1ebfn th\u1ee9c d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3, ba m\u1eb9 v\u00e0 tr\u1ebb c\u00f3 th\u1ec3 \u00e1p d\u1ee5ng m\u1ed9t s\u1ed1 b\u00ed quy\u1ebft sau \u0111\u00e2y:<\/p>\n<ul>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Hi\u1ec3u kh\u00e1i ni\u1ec7m d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3: \u0110\u1ec3 hi\u1ec3u \u0111\u01b0\u1ee3c b\u00e0i t\u1eadp th\u00ec tr\u01b0\u1edbc h\u1ebft ch\u00fang ta ph\u1ea3i n\u1eafm r\u00f5 kh\u00e1i ni\u1ec7m. N\u00ean h\u00e3y cho b\u00e9 hi\u1ec3u m\u1ed9t s\u1ed1 t\u1ef1 nhi\u00ean chia h\u1ebft cho 3 c\u00f3 ngh\u0129a l\u00e0 khi chia s\u1ed1 \u0111\u00f3 cho 3, kh\u00f4ng c\u00f3 s\u1ed1 d\u01b0 (s\u1ed1 d\u01b0 b\u1eb1ng 0).<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Nh\u1eadn bi\u1ebft c\u00e1c s\u1ed1 chia h\u1ebft cho 3: D\u1ef1a v\u00e0o c\u00e1c quy t\u1eafc v\u00e0 t\u00ednh ch\u1ea5t nh\u1eadn bi\u1ebft d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3 \u0111\u1ec3 c\u00f3 th\u1ec3 nhanh ch\u00f3ng x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c c\u00e1c s\u1ed1 c\u1ea7n t\u00ecm ch\u00ednh x\u00e1c.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">L\u00e0m quen v\u1edbi ph\u00e9p chia l\u1ea5y s\u1ed1 d\u01b0: H\u00e3y \u0111\u1ea3m b\u1ea3o c\u00e1c b\u00e9 n\u1eafm v\u1eefng ki\u1ebfn th\u1ee9c ph\u00e9p chia l\u1ea5y s\u1ed1 d\u01b0 \u0111\u1ec3 xem ph\u00e9p t\u00ednh c\u00f3 d\u01b0 kh\u00f4ng, t\u1eeb \u0111\u00f3 x\u00e1c \u0111\u1ecbnh d\u1ec5 d\u00e0ng s\u1ed1 \u0111\u00f3 c\u00f3 chia h\u1ebft cho 3 kh\u00f4ng nh\u00e9.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">V\u1eadn d\u1ee5ng trong c\u00e1c b\u00e0i to\u00e1n: H\u00e3y \u00e1p d\u1ee5ng d\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft s\u1ed1 chia h\u1ebft cho 3 trong c\u00e1c b\u00e0i to\u00e1n li\u00ean quan nh\u01b0 t\u00ecm c\u00e1c s\u1ed1 c\u00f3 t\u00ednh ch\u1ea5t \u0111\u1eb7c bi\u00eat, s\u1eafp x\u1ebfp c\u00e1c s\u1ed1, ph\u00e9p t\u00ednh chia\u2026 Ch\u1eb3ng h\u1ea1n nh\u01b0 t\u00ecm t\u1ea5t c\u1ea3 c\u00e1c s\u1ed1 chia h\u1ebft cho 3 t\u1eeb 1 \u0111\u1ebfn 50, t\u00ecm t\u1ed5ng c\u1ee7a c\u00e1c s\u1ed1 chia h\u1ebft cho 3 trong d\u00e3y s\u1ed1, \u2026<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">Luy\u1ec7n t\u1eadp th\u01b0\u1eddng xuy\u00ean: H\u1ecdc l\u00fd thuy\u1ebft th\u00f4i l\u00e0 ch\u01b0a \u0111\u1ee7, n\u00ean ba m\u1eb9 h\u00e3y kh\u00edch l\u1ec7, y\u00eau c\u1ea7u b\u00e9 th\u1ef1c h\u00e0nh l\u00e0m b\u00e0i t\u1eadp th\u01b0\u1eddng xuy\u00ean \u0111\u1ec3 n\u00e2ng cao kh\u1ea3 n\u0103ng t\u00ednh to\u00e1n cho b\u00e9 nh\u00e9.<\/p>\n<\/li>\n<li dir=\"ltr\">\n<p dir=\"ltr\" role=\"presentation\">X\u00e2y d\u1ef1ng ni\u1ec1m \u0111am m\u00ea h\u1ecdc to\u00e1n c\u00f9ng Shining Home &#8211; Gia \u0111\u00ecnh Anh Ng\u1eef Math: \u0110\u00e2y l\u00e0 m\u1ed9t \u1ee9ng d\u1ee5ng d\u1ea1y to\u00e1n t\u01b0 duy online d\u00e0nh cho tr\u1ebb m\u1ea7m non, ti\u1ec3u h\u1ecdc \u0111ang \u0111\u01b0\u1ee3c h\u00e0ng tri\u1ec7u ba m\u1eb9 tin d\u00f9ng. Thay v\u00ec cho b\u00e9 h\u1ecdc to\u00e1n theo c\u00e1ch truy\u1ec1n th\u1ee5 ki\u1ebfn th\u1ee9c nh\u01b0 tr\u00ean tr\u01b0\u1eddng, Shining Home &#8211; Gia \u0111\u00ecnh Anh Ng\u1eef Math s\u1ebd \u00e1p d\u1ee5ng nh\u1eefng ph\u01b0\u01a1ng ph\u00e1p d\u1ea1y to\u00e1n t\u00edch c\u1ef1c, hi\u1ec7n \u0111\u1ea1i \u0111\u1ec3 tr\u1ebb v\u1eeba \u0111\u01b0\u1ee3c ch\u01a1i, v\u1eeba \u0111\u01b0\u1ee3c h\u1ecdc m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3. C\u00f9ng v\u1edbi n\u1ed9i dung b\u00e1m s\u00e1t ch\u01b0\u01a1ng tr\u00ecnh GDPT s\u1ebd g\u00f3p ph\u1ea7n gi\u00fap b\u00e9 v\u1eeba x\u00e2y d\u1ef1ng \u0111\u01b0\u1ee3c n\u1ec1n t\u1ea3ng to\u00e1n h\u1ecdc v\u1eefng ch\u1eafc, t\u0103ng s\u1ef1 h\u1ee9ng th\u00fa khi h\u1ecdc v\u00e0 v\u1eeba h\u1ed7 tr\u1ee3 vi\u1ec7c h\u1ecdc tr\u00ean l\u1edbp t\u1ed1t nh\u1ea5t.<\/p>\n<\/li>\n<\/ul>\n<p style=\"text-align: center\"><iframe loading=\"lazy\" title=\"Gi\u1edbi thi\u1ec7u \u1ee9ng d\u1ee5ng Monkey Math\" width=\"1020\" height=\"574\" src=\"https:\/\/www.youtube.com\/embed\/7DsjpvHFrOs?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p dir=\"ltr\">\u0110\u0103ng k\u00fd ngay \u0111\u1ec3 \u0111\u01b0\u1ee3c t\u01b0 v\u1ea5n mi\u1ec5n ph\u00ed v\u00e0 nh\u1eadn \u01b0u \u0111\u00e3i l\u00ean t\u1edbi 40% ba m\u1eb9 nh\u00e9.<img loading=\"lazy\" decoding=\"async\" style=\"margin-left: auto;margin-right: auto\" class=\"lazyload\" src=\"https:\/\/external-content.duckduckgo.com\/iu\/?u=https:\/\/vnmedia.monkeyuni.net\/upload\/web\/img\/dangkyngay.png\" alt=\"\" width=\"200\" height=\"40\"><\/p>\n<h2 dir=\"ltr\"><span class=\"ez-toc-section\" id=\"Ket_luan\"><\/span>K\u1ebft lu\u1eadn<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p dir=\"ltr\">\n<p dir=\"ltr\">Tr\u00ean \u0111\u00e2y l\u00e0 nh\u1eefng th\u00f4ng tin chia s\u1ebb ki\u1ebfn th\u1ee9c c\u01a1 b\u1ea3n v\u1ec1 d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3. \u0110\u00e2y l\u00e0 m\u1ed9t chuy\u00ean \u0111\u1ec1 to\u00e1n kh\u00e1 quan tr\u1ecdng, v\u00ec t\u00ednh \u1ee9ng d\u1ee5ng trong h\u1ecdc t\u1eadp v\u00e0 th\u1ef1c ti\u1ec5n r\u1ea5t cao. N\u00ean ba m\u1eb9 h\u00e3y trang b\u1ecb cho b\u00e9 k\u1ef9 n\u1ec1n t\u1ea3ng n\u00e0y \u0111\u1ec3 gi\u00fap con \u0111\u1ea1t \u0111\u01b0\u1ee3c th\u00e0nh t\u00edch h\u1ecdc t\u1eadp t\u1ed1t nh\u1ea5t nh\u00e9.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Vi\u1ec7c nh\u1eadn bi\u1ebft \u0111\u01b0\u1ee3c d\u1ea5u hi\u1ec7u chia h\u1ebft cho 3 s\u1ebd gi\u00fap c\u00e1c em gi\u1ea3i b\u00e0i t\u1eadp v\u00e0 t\u00ednh to\u00e1n nhanh ch\u00f3ng h\u01a1n. V\u1eady th\u1ebf n\u00e0o l\u00e0 s\u1ed1 chia h\u1ebft cho 3, \u0111\u1eb7c \u0111i\u1ec3m nh\u1eadn bi\u1ebft v\u00e0 c\u00e1ch gi\u1ea3i nh\u01b0 th\u1ebf n\u00e0o? H\u00e3y c\u00f9ng t\u00ecm hi\u1ec3u r\u00f5 h\u01a1n ngay trong b\u00e0i vi\u1ebft sau \u0111\u00e2y nh\u00e9&#8230;.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[100],"tags":[],"class_list":["post-14252","post","type-post","status-publish","format-standard","hentry","category-kien-thuc"],"_links":{"self":[{"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/posts\/14252","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/comments?post=14252"}],"version-history":[{"count":1,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/posts\/14252\/revisions"}],"predecessor-version":[{"id":17024,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/posts\/14252\/revisions\/17024"}],"wp:attachment":[{"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/media?parent=14252"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/categories?post=14252"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ckconitsha.com\/vn\/wp-json\/wp\/v2\/tags?post=14252"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}