Choose a rule and sort
Keep one rule while sorting objects, then change the rule and sort again.
Start with the activity ↓Can the same objects be grouped differently?
Choose the rule first. When sorting by shape, keep the same shapes together despite size differences. A different rule makes different groups.
Some toys are mixed together. ‘Put the same ones together’ may be unclear. First decide whether same means the same shape or the same size.
If the rule is shape, large and small circles belong together. A large circle and a large triangle do not. Switching rules midway answers different questions.
Select an object, then choose its group. Keep unplaced objects separate so none is missed or counted twice. In this activity, each object belongs to exactly one group.
After finishing, sort by size instead. The groups change, but the total count does not because nothing was added or removed. Sorting changes the grouping, not the objects.
Listen one paragraph at a time
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Now check it yourself
Choose shape or size. Tap one object, then a group button. No dragging is needed.
1. Choose an unplaced object.
2. Choose its group.
- Circle
- None placed
- Triangle
- None placed
- Square
- None placed
0 of six objects placed.
These objects each belong to one shape group and one size group. Overlapping classifications are a later topic.
Try it away from the screen
Sort safe toys. Let each family member choose a rule and explain their grouping.
Can you explain another example?
Check your idea 1
Check your idea 2
Can you explain it in a new setting?
Sort the same objects in two ways and name each rule.
Speak, point or draw on paper. Check whether your own explanation includes these ideas.
Continue reading, or pause here
How can we remember the groups after putting the objects away? Next, record them in a table.