Solve problem 3 on page 138 of Math 4 textbook

Solution Guide for exercise 3 on page 138 of Math 4 textbook

Solution method:
- To multiply two fractions, multiply the numerator by the numerator and the denominator by the denominator
- Multiply a fraction by a natural number: Represent the natural number as a fraction with a denominator of 1, then multiply the numerator by the numerator and the denominator by the denominator. 

Here is a guide to solving exercise 3 on page 138 of the Math 4 textbook practice section. Additionally, this section includes four more exercises: Solve exercise 1 on page 138 of Math 4 textbook, Solve exercise 2 on page 138 of Math 4 textbook, Solve exercise 4 on page 138 of Math 4 textbook, and Solve exercise 5 on page 138 of Math 4 textbook. Let's explore the instructions for solving Math 4 page 138 to excel in 4th-grade Mathematics!