3
Sorting in different ways
Learner’s Book 1: Unit 7, p. 101
GoalSort the same group in two different ways and give each set a label.
New words
rule · what the things in a set have the samelabel · the name of a setdifferent · not the same
Explanation
One group can be sorted in more than one way. Look at four things: a red cap, a blue cap, a red cup and a blue cup. One way to sort them is by colour: the red things go in one set and the blue things in another set. Another way is by kind: the caps go in one set and the cups go in another set. Always say your rule and write a label for each set. A good rule is clear, so that every thing has just one place.
A group of 4 things
| red cap | blue cap | red cup | blue cup |
Worked examples
| red | blue |
|---|---|
| cap | cap |
| cup | cup |
| caps | cups |
|---|---|
| red | red |
| blue | blue |
Two different rules gave two different ways to sort. The group of things did not change.
Class activity
Two-way sort: choose 6 things (for example 3 spoons and 3 forks, some big and some small). Sort them one way, take a photo or draw it, then mix them up and sort them another way. Can your partner find the second rule?
Practice
1
Big circle, small circle, big square, small square. One way is by shape. Name another way.
by size (big and small)
2
Sort into ‘has corners’ and ‘no corners’. How many shapes have no corners?
2 (the oval and the circle)
3
Cat, hen, dog, duck. Sort into feathers and no feathers. Which animals have feathers?
hen and duck
4
Can the same group be sorted in two different ways?
Yes, by using different rules.