🔢 Mathematics · Counting & Cardinality
One-to-one counting
One-to-one correspondence when counting objects: each object is paired with exactly one number name
Typical age: 4–6 years
“If your child is counting a pile of grapes, do they touch or point to each one exactly once as they say each number — without skipping any or counting the same one twice?”
0 / 3 mastered
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Needs first
Nothing — this is a great starting point!
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- How Many in Total?REQUIRED
Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'
- Rote counting to 100REQUIRED
One-to-one correspondence requires knowing the number name sequence
- Counting objects to 20REQUIRED
Counting objects to answer 'how many?' requires one-to-one correspondence