3
Many ways to group
Discover Mathematics: Chapter 5
GoalSort things by shape, size and colour, and solve adding stories within 10.
New words
size · big or smallshape · round, square, and so oncolour · red, yellow, green and so onstory · a little tale with numbers in it
Explanation
The same things can be sorted in different ways. A pile of apples can be sorted by colour or by size. Choose one way and put each thing in a group. Then count each group. Look at the apples: 2 are big and 2 are small. An adding story joins two groups. Draw the first group, draw the second group, and count them all.
Worked examples
Ramy sorts his blocks by shape: 3 squares, 2 circles and 1 triangle.
Sorted by colour, the orange things are the carrot and the orange. The yellow things are the banana and the lemon.
Mina has 4 pencils. Seif has 3 pencils. Together they have 4 + 3 = 7 pencils.
Class activity
Sort the shoes. Gather the family's shoes by the door. Sort them first by size, big and small, then by colour. Count each group, and say how many shoes there are altogether.
Practice
1
Sort by size. How many big teddies and how many small teddies?
2 big and 3 small
2
What is 6 + 2?
8
3
Hossam has 5 stickers. Nada gives him 4 more. How many stickers does he have?
9
4
Which two things have the same shape?
The orange and the tennis ball. Both are round.
5
What is 7 + 3? Look at the ten-frame.
10