Cardinality principle: the last number said when counting a set tells how many objects are in the set, regardless of arrangement or order counted
After you count Leo's apples for a snack, you already know how many there are. You do not need to count again. The last number you say is the total.
Mia lines up 5 apples and counts them: 1, 2, 3, 4, 5. Then she puts them in a pile. She does not need to count again. It is still 5 apples.
Sometimes the things you count sit in two groups. Push them together and count them all: 1, 2, 3, 4, 5, 6. The total is 6. Do not start again at 1 for the second group. You can count left to right or right to left. The total stays the same.
When two groups sit close together, point at each thing as you count. Then nothing gets a number twice.
The last number you count is the total, no matter the order, the arrangement, or how many groups you started with.
At Meadow Lane you counted the strawberry plants, one finger on one plant. Today the berries are ripe.
Leo picks 4 berries. Mia picks 2. They tip both baskets into one bowl. How many berries are in the bowl?
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