Addition and subtraction: two-digit and single-digit numbers

Introduction

Build on segments 1.8, 1.9 and 1.10 to equip children with useful strategies for addition and subtraction of a single-digit number to/from two-digit numbers.

Teaching points

• Teaching point 1: Knowledge of the number line, and quantity values of numbers, can be applied to add/subtract one to/from a given two-digit number.
   
• Teaching point 2: Known facts for the numbers within ten can be applied to addition/subtraction of a single-digit number to/from a two-digit number.
   
• Teaching point 3: Knowledge of numbers which sum to ten can be applied to the addition of a single-digit number and two-digit number that sum to a multiple of ten, or subtraction of a single-digit number from a multiple of ten.
   
• Teaching point 4: Known strategies for addition or subtraction bridging ten can be applied to addition or subtraction bridging a multiple of ten.