Page 39 - Math Skill - 5

The Four Fundamental Operations 37

Exercise 3.7

1. The cost of 125 games is ` 1,23,125. Find the cost of one game.
2. The product of two numbers is 1,02,35,445. If one number is 445, find the other number.

3. The product of two numbers is 15,62,500. If one number is 625, find the other number.
4. How many hours are there in 8,60,400 minutes?

5. What should be multiplied by 584 to get 4,91,728?
6. Product of two numbers is 3,16,665. If one number is 155, find the other number.

7. 175 biscuits are to be packed in a poly-pack. How many poly-packs are required to pack
2,22,075 biscuits?

8. What least number should be subtracted from 3,16,579 to make it exactly divisible by 375?
(Hint: Find the remainder)

Simplification of Numerical Expressions

A combination of numbers connected by one or more basic operations like +, –, × or ÷, is called
a numerical expression.
For example, 18 ÷ 9 + 2 – 1; 25 – 3 × 4 + 6 ÷ 2, etc. are numerical expressions.

We follow certain rules while solving these expressions. Division (D)
The order of operations is as followed:

(i) Division (ii) Multiplication Multiplication (M)
(iii) Addition (iv) Subtraction.
Addition (A)
We call it DMAS rule.
Let’s learn this through examples. Subtraction (S)

Let’s Attempt

Example 1: Simplify: 70 – 48 ÷ 6 × 3 + 9 Example 2: Simplify: 143 – 15 + 12 × 8 ÷ 2

Solution: 70 – 48 ÷ 6 × 3 + 9 D Solution: 143 – 15 + 12 × 8 ÷ 2 D

= 70 – 8 × 3 + 9 = 143 – 15 + 12 × 4
M M
= 70 + 9 – 24
= 143 – 15 + 48
= 79 – 24 A A
= 143 + 48 – 15
= 55
S S
= 191 – 15

= 176