Addition and Subtraction: Mental Strategies

KS3 Numeracy Year 7
This unit is part of Around ARE Consolidating Numeracy

Objectives

Day 1

  • Number bonds to 100: addition and subtraction; counting up.

Day 2

  • Mental addition of 2-digit numbers, including decimal numbers.

Day 3

  • Mental subtraction of 2-digit numbers, including decimal numbers, by counting up.

Lesson Planning

Day 1

Check-up

Use pairs to 100 (addition and subtraction).

Follow-up

Use the 1-100 grid to find complements to 100.

Day 2

Check-up

Use mental strategies to add pairs of 2-digit whole numbers and 2-digit numbers with one decimal place.

Follow-up

Focus on three different mental strategies to add pairs of 2-digit whole numbers and 2-digit numbers with one decimal place.

Day 3

Check-up

Use ‘counting up’ to subtract pairs of 2-digit whole numbers and 2-digit numbers with one decimal place.

Follow-up

Use ‘counting up’ on the number line to subtract pairs of 2-digit whole numbers and 2-digit numbers with one decimal place.