NCERT Solutions for Class 7th Maths Chapter 4 In-text Questions — Decimal Multiplication
Book page 69 Updated on2026-09-19
Q1.
Example 1: Arshad goes to a stationery shop and purchases 5 pens. If one pen costs ₹9.5 (9 rupees and 50 paisa), how much should he pay the shopkeeper?
Why it happens: ₹9.5 is 9 rupees and 50 paisa. Five pens cost 45 rupees plus 5 × 50 = 250 paisa = ₹2.50. Together ₹47.50 — the very same number.
Q2.
What operation must we use here?
Answer
Multiplication.
Each pen costs the same amount, and there are 5 of them. Adding the same number again and again is multiplication.
9.5 + 9.5 + 9.5 + 9.5 + 9.5 = 9.5 × 5
Why it happens: repeated addition of equal amounts is exactly what multiplication was invented for. This does not change just because the amount is a decimal — 9.5 is a number like any other.
Q3.
Example 2: A car travels 12.5 km per litre of petrol. What is the distance covered with 7.5 litres of petrol?
Why it happens: each denominator is 10, so their product is 100 — two zeroes, hence two digits after the point in the answer. Notice that 12.5 and 7.5 have one decimal place each, and 1 + 1 = 2. That is the rule the chapter is heading towards.
Check it yourself: 7.5 litres is a little less than 8 litres, and 8 × 12.5 = 100 km. So the answer must be a little under 100 km. 93.75 fits.