Solving Exercise 2 on Page 66 of Math 5 Textbook

Buzz

Ngày cập nhật gần nhất: 15/4/2026

Solving Exercise 2 on Page 66 of Math 5 Textbook: Dividing a decimal number by 10, 100, 1000.., Mental calculation and comparison of results:

Guide to solving Exercise 2 on Page 66 of Math 5 Textbook

Problem:
Mental calculation and comparison of results:
a) 12.9 ÷ 10 and 12.9 x 0.1;
b) 123.4 ÷ 100 and 123.4 x 0.01;
c) 5.7 ÷ 10 and 5.7 x 0.1;
d) 87.6 ÷ 100 and 87.6 x 0.01.

Solution Method:
We perform multiplication of a decimal number by 0.1; 0.01; 0.001;... and division of a decimal number by 10; 100; 1000;... as usual, then compare the results of these two operations.

Answers:
a) 12.9 ÷ 10 = 12.9 x 0.1 = 1.29 b) 123.4 ÷ 100 = 123.4 x 0.01 = 1.234
c) 5.7 ÷ 10 = 5.7 x 0.1 = 0.57 d) 87.6 ÷ 100 = 87.6 x 0.01 = 0.876

Section solution to exercise page 66 math 5, dividing a decimal number by 10,100,1000.. consists of 3 exercises, Next is solving exercise 2 on page 66 of math 5 textbook. Mytour provides detailed answer hints and solution methods for solving Exercise 1 on Page 66 Math 5 Textbook and Exercise 3 on Page 66 Math 5 Textbook, students need to grasp the knowledge of this lesson.

Frequently Asked Questions

What is the method for dividing a decimal number by 10, 100, or 1000?

The method involves moving the decimal point to the left by the number of zeros in the divisor. For example, dividing by 10 moves it one place left, while dividing by 100 moves it two places left.

How can students compare the results of division and multiplication of decimal numbers?

Students can compare results by performing both operations on the same decimal number. For example, dividing 12.9 by 10 gives 1.29, which is the same as multiplying 12.9 by 0.1.

What are the solutions for Exercise 2 on Page 66 of the Math 5 Textbook?

The solutions are as follows: a) 12.9 ÷ 10 = 1.29; b) 123.4 ÷ 100 = 1.234; c) 5.7 ÷ 10 = 0.57; d) 87.6 ÷ 100 = 0.876.

Why is mental calculation important when working with decimal numbers?

Mental calculation enhances number sense and improves accuracy. It allows students to quickly verify results and understand the relationships between different mathematical operations involving decimals.

Mytour's content is for customer care and travel encouragement only, and we are not responsible.

For errors or inappropriate content, please contact us at: [email protected]