Table of Contents
Calculating the value of grade 3 expression is one of the basic but important mathematical forms, often appears in exams. So, in the following article, Shining Home – Gia đình Anh Ngữ will share details on how to calculate the expression value, and some common types of exercises with solutions for them to understand.
Knowledge to remember when calculating the value of grade 3 math expressions
If in the 1st and 2nd grade math programs, they will only get used to the exercises with individual calculations. However, when entering the 3rd grade math, it will be acquainted with the problems with many calculations combined together, asking them to calculate. This is the “value of the expression”.
The concept of expression and value of the expression
In mathematics, numerical expressions are calculations and numbers. When we solve those calculations, we will get a result called the value of the expression.
So, the value of the expression: is the result after performing the calculations in the expression.
The forms of expressions and the order of calculation
The forms of 3rd grade math exercises are quite diverse, the expression part will have the following forms and order as follows:
Form 1: The expression contains only calculations and priority levels: plus, subtracting or multiplication, dividing: performing the calculation from left to right.
Example: Calculate the value of the expression:
a) 93: 3 x 7 b) 15 x 7: 5
Instructions for solving
a) 93: 3 x 7 = 31 x 7 = 217
b) 15 x 7: 5 = 105: 5 = 21
Form 2: The expression includes addition, subtraction, multiplication, division, we perform the division first and subtract later;
Example: Write the following expressions and calculate the value of those expressions:
a) Calculate the product of 15 and 4 and then plus 42.
b) Calculate the sum of 98 and 37 and subtract 74.
Instructions for solving
a) 15 x 4 + 42 = 60 + 42 = 102.
b) 98 + 37 – 74 = 135 – 74 = 61.
Form 3: The expression contains parentheses (), we will perform the calculation in brackets first and outside the parentheses.
Example: Calculate the value of the following expressions:
a) 99927: (10248: 8 – 1272)
b) (10356 × 5 – 780): 6
Instruct:
a) 99927: (10248: 8 – 1272) = 99927: (1281 – 1272) = 99927: 9 = 11103.
b) (10356 × 5 – 780): 6 = (51780 – 780): 6 = 51000: 6 = 8500
Attention:
Case 1: If the expression has an adjacent multiplication and division, but between calculations with additional signs or subtraction, we will perform that multiplication and division. Then continue to consider the sign of the remaining calculations in the expression and apply it according to the above forms of expressions.
For example: 128 × 2 + 367 × 3 – 895 + 476 × 4 – 2018 + 182
= 256 + 1101 – 895 + 1904 – 2018 + 182
= 1357 – 895 + 1904 – 2018 + 182
= 462 + 1904 – 2018 + 182
= 2366 – 2018 + 182
= 348 + 182
= 530
Or 128 × 2 + 367 × 3 – 895 + 476 × 4 – 2018 + 182
= 256 + 1101 – 895 + 1904 – 2018 + 182
= 1357 – 895 + 1904 – (2018 – 182)
= 462 + 1904 – 1836
= 2366 – 1836
= 530
Case 2: If the expression has a division and multiplication adjacent to each other, we will have to perform in order from the left and then right instead of calculating the multiplication first and then to divide. Then continue to consider the remaining calculation sign in the expression according to the rules given.
For example: 195615: 945 × 13 – 356 + 1024
= 207 × 13 – 356 + 1024
= 2691 – 356 +1024
= 2335 + 1024
= 3359
Rules for calculating the value of grade 3 expressions
Based on the above types of expressions, we can draw important rules when calculating the following expression value:
-
The expression has only 2 calculations of addition and subtraction or multiplication and division, we only need to follow the order from left to right.
-
The expression includes the addition of addition, subtraction, multiplication and division, people need to follow the rule of “first and subtracted”.
-
In the expression containing parentheses (), we will have to perform the calculation in the brackets first before coming outside.
Guide to solving 3rd grade Math textbook exercises calculating the value of the expression
Here are some exercises in the 3rd grade math program with the guidelines for the students to refer to:
Lesson 1: Calculate the value of the expression 🙁 Page 79)
a) 205 + 60 + 30
268 – 68 + 17
b) 462 – 40 + 70
287 – 7 – 80
Instructions for solving
a) 205 + 60 + 30 = 265 + 30
= 295
268 – 68 + 17 = 200 + 17
= 217
b) 462 – 40 + 70 = 422 + 70
= 492
287 – 7 – 80 = 280 – 80
= 200
Lesson 2: Calculate the value of the expression (page 79)
a) 15 × 3 × 2
48: 2: 6
b) 8 × 5: 2
81: 9 × 7
Instructions for solving
a) 15 × 3 × 2 = 45 × 2 = 90
48: 2: 6 = 24: 6 = 4
b) 8 × 5: 2 = 40: 2 = 20
81: 9 × 7 = 9 × 7 = 63
Lesson 3: (page 79) Fill in the sign ; = Go to the following dot
55 × 5: 3 …. 32
47 … .. 84 – 34 – 3
20 + 5 … .. 40: 2 + 6
Instructions for solving
55 × 5: 3> 32
47 = 84 -34 -3
20 + 5 <40: 2 + 6
Lesson 4 🙁 Page 79) Each package of noodles weighs 80g, each box weighs 455g. Ask 2 packs of noodles and 1 box of milk weighing how many grams?
Instructions for solving
2 packs of noodles and 1 box of milk weighing the number of grams are:
80 + 80 + 455 = 615 grams
Answer: 615 grams
Instructions for solving math exercises on page 80 textbooks:
Lesson 1: (Page 80) Calculate the value of the expression:
a) 253 + 10 × 4
41 × 5 – 100
93 – 48: 8
b) 500 + 6 × 7
30 × 8 + 50
69 + 20 × 4
Instructions for solving
a) 253 + 10 × 4 = 253 + 40 = 293
41 × 5 – 100 = 205 – 100 = 105
93 – 48: 8 = 93 – 6 = 87
b) 500 + 6 × 7 = 500 + 42 = 542
30 × 8 + 50 = 240 + 50 = 290
69 + 20 × 4 = 69 + 80 = 149
Lesson 2: (Page 80) Write correctly, wrongly inscribed in the following blanks
a) 37 – 5 × 5 = 12
180: 6 + 30 = 60
30 + 60 × 2 = 150
282 – 100: 2 = 91
b) 13 × 3 – 2 = 13
180 + 30: 6 = 35
10 + 60 × 2 = 180
282 – 100: 2 = 232
Instructions for solving
a) 37 – 5 × 5 = 12 đ
180: 6 + 30 = 60 VND
30 + 60 × 2 = 150 VND
282 – 100: 2 = 91 s
b) 13 × 3 – 2 = 13 s
180 + 30: 6 = 35 s
10 + 60 × 2 = 180 s
282 – 100: 2 = 232 VND
Lesson 3: (page 80) Mom picked 60 apples, she picked 35 apples. The number of apples of her mother and her are all in 5 boxes. Ask how many apple each box each?
Instructions for solving
The total number of mother apples and she picked is:
60 + 35 = 95 (fruit)
Each box has the number of apples:
95: 5 = 19 (Fruit)
Exercise calculating the value of 3rd grade expressions
In addition to the exercise of the expression value in the 3rd grade Mathematics textbook, Shining Home – Gia đình Anh Ngữ will summarize some more related exercises so that they can apply knowledge to practice effectively:
Exercise 1: Calculate the value of the following expressions:
150 + 10 x 3 =
40 x 5 – 125 =
90 – 48: 8 =
135 + 7 x 6 =
69 + 20: 5 =
132 + 5 x (7 + 8) =
Exercise 2: Correct (đ), wrong (s) in the following boxes:
32 – 5 x 5 = 7
180: 6 + 35 = 75
30 + 60 x 2 = 150
282 – 82: 2 = 100
30 + 20 x 2 = 80
131 – 32 x 3 = 25
Exercise 3: Two men and Huy go to pick apples in the garden. The male friend picked 30 fruits, Huy picked 10 less than men. The number of apples you are picked is arranged evenly in 5 boxes. Ask how many apples for each box?
Exercise 4: Fill in the mark (>, =, <) appropriate to the blanks below
135 + 5 x 3 …. 125 + 5 x 5
189: 3 x 8 …. 189: 9 x 8
12 + 20 x 2 …. 16 + 50: 2
156 + 20: 2 …. 156 + 5x 2
145: 3 + 10 …. 145 – 20 x 2
Exercise 5:
a) (563+ 126) x 2
b) 4 x 108 + 157 =
c) 1243 – 366: 3
d) 435: 5 + 582 =
e) 153 + 638 – 470 =
Exercise 6: Calculate the expression value:
a. 3 x (89424 – 72813)
b. 24368 + 15336: 3
c. 72009: 3 x 2
d. 2 x 45000: 9
e. 15 840 + 32046: 7
f. 32 464: 8 – 3956
g. 15 840 + 8972 x 6
i. (12 879 – 9 876) x 4
h. 239 + 1267 x 3 =
l. 2505: (403 – 398) =
Exercise 7: Calculate the value of the expression:
(4672 + 3583): 5
1956 + 2126 x 4
4672 – (3583 – 193)
2078 – 3328: 4
Exercise 8: Write the expression and calculate the value of the expression:
a. 45 divided by 5 cores with 7
b. 1535 divided by 5 plus 976
c. 236 multiplied by 2 minus 195
d. 1562 divided by 3 cores with 4
Exercise 9: Calculate the value of the following expressions
a) 78 x 6 + 345 c) 56 + 67 x 6
b) 378 + 324: 3 d) 288: 6 x 7
Exercise 10. 25x4x7; 216 × 3: 6; 990: 3: 6; 480: 8 x 7; 125 × 2: 5
Experience in conquering the 3rd grade Mathematics calculates the value of expression
For children who are new to 3rd grade, the implementation of math problems with many combined calculations will certainly be more difficult than the mathematics such as grade 1 and 2nd grade. So, to help children can conquer this form of math more and more easy to understand, more effectively, here are some experiences for them to refer and apply.
Building a mathematical platform with Shining Home – Gia đình Anh Ngữ Math
Calculating the value of grade 3 expressions is basically normal calculations. So, to make it easier for them to understand and be more interested in studying 3rd grade math, do not miss the Shining Home – Gia đình Anh Ngữ Math tool. This is the application of online mathematical teaching for children from preschool to elementary school, with the content built closely to the latest education program of the Ministry. In order to help children build a solid mathematical platform, and support learning math knowledge better.
The special feature of Shining Home – Gia đình Anh Ngữ Math is to apply many different teaching methods to help children feel more interested instead of just conveying common knowledge like schools. Include:
-
Applying positive teaching methods: stimulating creativity, children actively ask questions to understand the root of the problem given in mathematics.
-
Learning through the game: Playing and learning but effective. I am interested, voluntarily learning without parents reminders.
-
Study with supplementary exercises: Help your child develop semi -motor and raw motor skills through solving practical problems.
Make sure that after completing the course with Shining Home – Gia đình Anh Ngữ Math will help your child:
-
Develop 5 mathematical competencies under the new education program & form a logical thinking habit from an early age
-
Development of thinking & intelligence in the golden stage of brain development
-
Building mathematical platform & supporting classroom study effectively
-
Develop synchronous thinking & language to help children study well in both math and English
>>> free experience now!
To better understand Shining Home – Gia đình Anh Ngữ Math, parents can refer to the following video or register for detailed advice:
https://www.youtube.com/watch?v=7dsjpvhfros
Master the rules of calculating the value of the expression
To calculate the value of an expression, it requires children to understand the three rules mentioned above. Parents can explain each rule in detail for children to understand, regularly check their old knowledge to ensure the situation of “studying first and after”.
Do homework, practice regularly
Practicing and practicing regularly is considered the best method to support improving knowledge, especially for young children. After grasping the rules and understanding how to solve the actual value, parents should give them regular practice, do homework every day, or participate in games, solve puzzles, participate in competitions on the Internet, …
Through regular training will help your child's brain work better, improve calculation skills and promote more carefully when learning effectively.
Teaching experience calculates the value of expressions through thinking math
Mathematics is considered a method of learning combining many skills. In addition to solving exercises in books, parents can combine with solving math contact with practice, intuitive tools. Through that will help increase your baby's ability to absorb and the interest in wanting to conquer problems more effectively.
Conclude
Above are the sharing of knowledge of calculating the value of 3rd grade expression so that they can refer to them and their parents as well as accompany their children on the way to conquer this subject and knowledge. If parents plan to learn about the tool to support children to learn math more effectively, do not miss Shining Home – Gia đình Anh Ngữ Math.
Nguồn: http://www.ckconitsha.com/vn/ Tác giả: Nguyễn Lân dũng
Giáo sư Nguyễn Lân Dũng là một nhà khoa học tiêu biểu của Việt Nam trong lĩnh vực vi sinh vật học, với hơn nửa thế kỷ gắn bó với công tác giảng dạy và nghiên cứu (). Ông sinh trưởng trong một gia đình có truyền thống hiếu học, là con trai của Nhà giáo Nhân dân Nguyễn Lân. Trong suốt sự nghiệp, Giáo sư đã đảm nhận nhiều vai trò quan trọng như Chủ tịch Hội các ngành Sinh học Việt Nam, Đại biểu Quốc hội và được vinh danh với danh hiệu Nhà giáo Nhân dân vào năm 2010.