Solving Math for grade 3 on pages 100, 101 of Canh Dieu Workbook volume 2
Solving exercises on pages 100, 101 of Math 3 Workbook 2, Canh Dieu book
Reviewing what has been learned
1. Solve Exercise 1 Page 100 Math Grade 3 Textbook
Problem: Set the calculation and then calculate.
a) + Write the calculation vertically so that the numbers in the same row are aligned.
+ Perform addition, subtraction of numbers from right to left.
b) + Set the calculation for multiplication and division.
+ For multiplication: Multiply in order from right to left.
+ For division: Divide successively from left to right.
Answer:
2. Solve Exercise 2 Page 100 Math Grade 3 Textbook
Problem: Calculate the value of the following expressions:
- If the expression contains parentheses, perform the calculations within the parentheses first.
- If the expression contains multiplication, division, addition, and subtraction, perform multiplication and division first, then perform addition and subtraction.
Answer:
(12,726 + 10,618) x 2 = 23,344 x 2
= 46,688
54,629 - 48,364 : 4 = 54,629 - 12,091
= 42,538
3. Solve Exercise 3 Page 100 Math Grade 3 Textbook
Problem: a) The frame of a painting is in the form of a square with a side length of 75 cm. What is the perimeter of that painting in meters?
b) A decorative pattern on a piece of traditional cloth is in the form of a rectangle with a length of 21 cm and a width of 9 cm. Calculate the area of that pattern.
Solution:
a) To find the perimeter of a square, multiply the length of one side by 4.
b) To find the area of a rectangle, multiply the length by the width (in the same unit of measurement).
Answer:
a) The perimeter of the picture frame is:
75 x 4 = 300 (cm)
Convert: 300 cm = 3 m.
b) The area of the decorative piece is:
21 x 9 = 189 (cm2)
Answer: a) 3 m
b) 189 cm2
4. Solve Problem 4 Page 101 of Grade 3 Math Textbook
Problem: The table below shows the number of elementary schools in Vietnam from 2015 to 2019:
Read the table above and answer the questions:
a) Which academic year has the highest number of elementary schools?
b) How many schools are there fewer in the academic year 2017 - 2018 than in the academic year 2016 - 2017?
c) Round the number of elementary schools in Vietnam in the table to the nearest thousand and read the rounded numbers.
d) Tuấn commented: 'The number of elementary schools in Vietnam is decreasing over the academic years.' Do you agree with Tuấn's comment?
Solution: Use the data table to answer the questions.
Answer:
a) The academic year 2015 - 2016 has the highest number of elementary schools.
b) The number of elementary schools in the academic year 2017 - 2018 is fewer than the number of elementary schools in the academic year 2016 - 2017 by: 15,052 - 14,937 = 115 (schools).
c) The number of elementary schools in Vietnam in the academic years 2015 - 2016, 2016 - 2017, and 2017 - 2018 is about 15,000 schools.
The number 15,000 is read as: fifteen thousand.
The number of elementary schools in Vietnam in the academic year 2018 - 2019 is about 14,000 schools.
The number 14,000 is read as: fourteen thousand.
So the number of elementary schools in Vietnam is decreasing over the academic years. Tuấn's comment is correct.
- See more: Solving exercises on pages 105, 106 of Grade 3 Math Textbook Volume 2, Canh Dieu book
5. Solve Problem 5 Page 101 of Grade 3 Math Textbook
Problem: a) Estimate the number of grams of tofu in the jar more.
b) Estimate the number of milliliters of water in the big basin more.
b) Estimate the number of milliliters of water in the big basin more.
Solution:
Observe the picture, estimate how many times the amount of tofu in the jar is more than the amount of tofu in the smaller jar, and how many times the amount of water in the large basin is more than the amount of water in the small basin.
Fill in the corresponding quantities in the blank boxes.
Answer:
6. Solve Problem 6 Page 101 of Grade 3 Math Textbook
Problem: a) Choose two items you want to buy in the picture below and calculate the amount of money needed to pay.
b) With 100,000 dong, choose the items in question a to buy the most variety.
Solution:
Observe the picture, determine the price of each item to answer the question.
To buy the most variety of items, we will choose items from low to high prices.
Answer:
a) Choose two items you want to buy in the picture above and calculate the amount of money needed to pay.
For example: Choose two items are a ruby and a book.
The amount of money to pay is:
23,000 + 22,000 = 45,000 (dong)
b) With 100,000 dong, we can buy a ruby, a book, and a toy plane.
Solving exercises on pages 100, 101 of Grade 3 Math Textbook Volume 2, Canh Dieu book has provided detailed instructions for solving the exercises. Review what you have learned before consulting to understand how to do it.
