Numbers can Tell us Things

Class 6 Maths · Chapter 3: Number Play · NCERT Ganita Prakash section 3.1

Learn

Numbers can carry a message. Some children stand in a line and each one says a number. What could the numbers mean?

Each child says how many of their neighbours (the children right next to them) are taller: 0 if none, 1 if one, 2 if both.

Can the children at the ends say 2? No! They have only one neighbour each, so they can say only 0 or 1.

If they stand from shortest to tallest, everyone says 1, except the tallest at the end, who says 0.

Explore: tap two children to swap their places. Each child says how many neighbours are taller.

1. Arrange them so that everyone says 1, except one child who says 0.
2. Now make them say 0, 1, 2, 1, 0.
3. Make exactly two children say 2.

Remember

• Each child says the number of taller neighbours: 0, 1 or 2.
• Children at the ends have only one neighbour, so they never say 2.

Quick check

A child stands between two taller children. What does the child say?

1. 0
2. 1
3. 2
4. 3

Think about it

Can 5 children stand so that they say 0, 1, 2, 1, 0?

Practice

Practise with fresh questions at three levels (easy, medium, hard), some answered hands-on, with hints and worked answers. Get 4 of your last 5 right to finish the topic.