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NCERT Solutions Ganita Prakash Chapter 3 In-text Questions — Numbers can Tell us Things

Book page 55 & 56 Updated on2026-09-05

Q1.
Think about various situations where we use numbers. List five different situations in which numbers are used. See what your classmates have listed, share, and discuss.
Answer

Numbers are all around us. Five everyday situations in which we use them:

  1. Telling time — the school bell at 8:30, a 40-minute period, a train leaving at 6:15.
  2. Money — ₹20 for a plate of samosas, counting the change, saving pocket money.
  3. Measuring — your height in centimetres, 2 kg of onions, 1 litre of milk.
  4. Counting and marks — 42 children in the class, 87 marks out of 100, 6 runs off one ball.
  5. Addresses and codes — house number 14, PIN code 110016, a 10-digit mobile number, bus route 236.
Math Talk: Notice that the numbers do different jobs. ₹20 and 2 kg measure an amount, 42 children counts, but a PIN code or a bus route number only names something — you would never add two PIN codes!
Q2.
What do you think these numbers mean? (Some children in a park are standing in a line. Each one says a number: 0, 2, 1, 1, 0, 2, 1, 0)
Answer

Each child is telling us how many of the children standing next to them are taller than they are.

A child says 0 → neither neighbour is taller
A child says 1 → exactly one neighbour is taller
A child says 2 → both neighbours are taller

Look at the picture on page 55 and check it yourself. The first child says 0 because she has only one neighbour and that neighbour is shorter. The second child (the smallest girl) says 2 because the children on both her sides are taller. The tall boy in the middle says 0 because both his neighbours are shorter than him.

Why it happens: a child at either end of the line has only one neighbour, so an end child can only say 0 or 1 — never 2.
Q3.
Did you figure out what these numbers represent? Hint: Could their heights be playing a role? (The children now rearrange themselves and say 1, 0, 2, 0, 1, 2, 1, 0)
Answer

Yes — the numbers again say how many taller neighbours each child has. The children have only changed places; the rule has not changed.

Child (left to right)1st2nd3rd4th5th6th7th8th
Number said10201210

The second child is the tallest of the group, so he says 0. The child next to him is shorter than both his neighbours, so he says 2.

Check it yourself: add up all the numbers said. Here 1 + 0 + 2 + 0 + 1 + 2 + 1 + 0 = 7, which is one less than the 8 children. This always happens when all the heights are different — try it!
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