1Numbers to 10Ages 4–6 · PK–K

2Linear & Skip CountingAges 4–7 · PK–1

3The Decimal SystemAges 4–7 · PK–2

4Memorization of FactsAges 5–9 · K–3

5Passage to AbstractionAges 6–11 · 1–5

6FractionsAges 6–10 · 1–4

7Decimal FractionsAges 9–12 · 4–6

Beyond worksheets