Addition and Subtraction — Year 2

• Fact families and inverse operations

  Litnumia skill: Fact families and inverse operations

  Concrete–pictorial–abstract progression: bar models and number lines before formal columnar addition/subtraction with exchanging.

• Mental addition and subtraction of two-digit numbers

  Litnumia skill: Mental addition and subtraction of two-digit numbers

  Concrete–pictorial–abstract progression: bar models and number lines before formal columnar addition/subtraction with exchanging.