NCERT Solutions Ganita Prakash (Part 1) Chapter 3 In-text Questions — Decimal Place Value

Book page 61 Updated on2026-09-05

Q1.

We can ask similar questions about fractional parts: (a) How many thousandths make one unit? (b) How many thousandths make one tenth? (c) How many thousandths make one hundredth? (d) How many tenths make one ten? (e) How many hundredths make one ten?

Answer

	Question	Working	Answer
(a)	thousandths in one unit	1 ÷ ¹⁄₁₀₀₀	1000
(b)	thousandths in one tenth	¹⁄₁₀ = ¹⁰⁰⁄₁₀₀₀	100
(c)	thousandths in one hundredth	¹⁄₁₀₀ = ¹⁰⁄₁₀₀₀	10
(d)	tenths in one ten	10 ÷ ¹⁄₁₀ = 10 × 10	100
(e)	hundredths in one ten	10 ÷ ¹⁄₁₀₀ = 10 × 100	1000

Why it happens: every step you move to the right on the place value chart multiplies the count by 10. From "ten" to "tenth" is two steps (ten → one → tenth), so the count is 10 × 10 = 100. From "ten" to "hundredth" is three steps, giving 1000.

Tip: count the steps between the two place values on the chart. The answer is always 1 followed by that many zeros.

Q2.

Make a few more questions of this kind and answer them.

Answer

Here are some you can use, with their answers. Then write five of your own for a friend.

Question	Steps on the chart	Answer
How many hundredths make one unit?	2	100
How many thousandths make one hundred?	5	1,00,000
How many tenths make one hundred?	3	1000
How many ten-thousandths make one tenth?	3	1000
How many hundredths make one thousand?	5	1,00,000

Try This: turn it around — "One hundredth is what part of one ten?" Answer: ¹⁄₁₀₀₀.

Q3.

Can the quantity 4 2/10 be written as 42 (skipping the 1/10 in 2 × 1/10)? If yes, how would we know if 42 means 4 tens and 2 units or it means 4 units and 2 tenths?

Answer

No, we cannot. Writing it as 42 destroys the information.

4 tens and 2 units = 40 + 2 = 42
4 units and 2 tenths = 4 + ²⁄₁₀ = 4.2
These are completely different quantities — one is ten times the other and more.

The same problem shows up with 705, which could mean:

7 hundreds, 0 tens and 5 ones = 700 + 0 + 5 = 705
7 tens, 0 units and 5 tenths = 70 + 0 + ⁵⁄₁₀ = 70.5
7 units, 0 tenths and 5 hundredths = 7 + 0 + ⁵⁄₁₀₀ = 7.05

Why it happens: in place value the meaning of a digit comes from where it sits. Once we allow fractional places, the string of digits alone no longer tells us where the units place ends. So we mark it with a separator — the decimal point — and write 4.2, 70.5, 7.05.

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