Chapter 8: Grouping and Sharing

When friends sit together to eat, we share. When we pack mangoes in baskets, we group. Both grouping and sharing are super useful ideas in maths!

What we'll do

• Make equal groups of things.
• Use repeated addition to count groups quickly.
• Share things equally among friends.
• Take a first peek at multiplication and division.

The big idea

Suppose you have 4 plates and you put 3 mangoes in each plate. How many mangoes in all? You can count: 3, 6, 9, 12. You added 3 four times: 3 + 3 + 3 + 3 = 12. This is repeated addition, and it is what multiplication is all about. We can also say "4 groups of 3 is 12".

Sharing is the other side of the same idea. Suppose 12 mangoes are to be shared equally among 4 friends. We give one to each, then one more to each, and again ... until the mangoes finish. Each friend gets 3 mangoes. This is dividing, or sharing equally.

Grouping and sharing are everywhere , handing out sweets, arranging chairs in rows, packing eggs in trays of 6. When the groups are equal, counting becomes easy.

If groups are not equal, then it is not fair sharing. Two children should not get 5 chocolates while another gets only 1. Maths teaches us to be fair!

Let's play!

Bowls and beans. Take 15 beans and 3 bowls. Put the same number in each bowl. How many in one bowl?

Auto race. Imagine 5 autos and each one carries 2 passengers. How many passengers in all? Draw it.

Sweets for friends. You have 20 sweets and 4 friends. Share equally. How many does each get? Now try 18 sweets and 3 friends.

A small story

Pumpkin was throwing a chaupal party. He had 12 idlis and 4 hungry friends came over. He gave one idli to each friend, then another, then another. Each friend got 3 idlis and Pumpkin's plate was empty. "Fair and tasty!" everyone cheered.

Quick check

1. 2 + 2 + 2 + 2 = how many groups of 2?
2. There are 3 boxes with 4 chocolates each. How many in all?
3. Share 10 ladoos equally between 2 children. How many for each?
4. 5 friends each have 2 balloons. Total balloons?
5. 14 mangoes shared equally in 7 baskets , how many in each basket?

What did we learn?

• Equal groups can be counted by repeated addition.
• Multiplication is a fast way to add equal groups.
• Division is sharing things into equal groups.