NCERT Solutions for Class 7th Maths Chapter 3 In-text Questions — A Hundredth Part

Book page 53 Updated on2026-09-19

Q1.
What is the length of this smaller part? How many such smaller parts make a unit length?
Answer

Each one-tenth has been cut into 10 equal parts.

1 unit = 10 one-tenths
1 one-tenth = 10 smaller parts
So 1 unit = 10 × 10 = 100 smaller parts
Length of one smaller part = 1⁄100 of a unit (one-hundredth)
Number of such parts in a unit = 100
Why it happens: cutting each of the 10 tenths into 10 pieces gives 10 groups of 10 pieces, i.e. 100 pieces in all. Each piece is therefore one-hundredth of the whole unit.
Did you know? On your ruler, 1 cm is divided into 10 mm. If each mm were divided into 10 again, each tiny part would be 1⁄100 cm — about the thickness of a human hair.
Q2.
How many one-hundredths make one-tenth? Can we also say that the length is 4 units and 45 one-hundredths?
Answer
1⁄10 = 10⁄100
So 10 one-hundredths make one-tenth.

Yes — the folded paper measures 4 4⁄10 5⁄100, and

4⁄10 = 40⁄100
40⁄100 + 5⁄100 = 45⁄100
Length = 4 units and 45 one-hundredths = 4 45⁄100
Why it happens: "4 tenths and 5 hundredths" and "45 hundredths" describe the same amount, just grouped differently — like saying "4 tens and 5 ones" or "45 ones".
Tip: in decimal notation all three readings are the same number: 4.45.
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