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# Giải Toán lớp 5 trang 160, 161 Bài Luyện tập | Hay nhất – Tailieu.com

Are you looking to deepen your understanding of math concepts? One of the best ways to do that is by actively solving exercises in your textbooks and workbooks. By doing so, you’ll discover effective problem-solving methods for various math problems and be well-prepared for upcoming exams. In this article, we’ll provide step-by-step solutions for exercises 1, 2, and 3 on pages 160 and 161 of your Grade 5 math book. These solutions are generously shared by our experienced team of experts, and we are delighted to offer them to you for free. So let’s dive in and explore these exercises together!

## Exercise Solutions on Pages 160 and 161

### Exercise 1: Addition and Subtraction of Fractions

To calculate the sum or difference of two fractions with different denominators, we need to find a common denominator and then perform the addition or subtraction.
Remember, when an expression contains only addition or subtraction, we evaluate it from left to right.

Solution:

### Exercise 2: Convenient Calculation of Fractions

To quickly calculate the sum of fractions or decimal numbers that add up to a whole number, we can apply the commutative and associative properties of addition. Additionally, the formula a – b – c = a – (b+c) can be used.

Solution:

### Exercise 3: Budgeting and Savings

A working-class family allocates their monthly income as follows: 3/5 of their income is spent on family meals and children’s education, 1/4 is spent on rent and other expenses, and the rest is saved.

a) What percentage of their income does the family save each month?
b) If their monthly income is 4,000,000 Vietnamese dong, how much do they save each month?

Solution:

• We consider the family’s income as 1 unit.
• To find the fraction representing the total expenses, we calculate 3/5 + 1/4.
• To find the fraction representing the amount saved, we subtract the fraction representing the total expenses from 1.
• Finally, we convert the result to a percentage.

a)
The percentage of income spent by the family:
3/5 + 1/4 = 17/20 = 85%

The percentage of income saved by the family:
100% – 85% = 15%

b)
The amount of money the family saves each month:
(4,000,000 x 15) / 100 = 600,000 Vietnamese dong

a) They save 15% of their income.
b) They save 600,000 Vietnamese dong per month.