Addition and subtraction: two-digit numbers and multiples of ten

Spine 1: Number, Addition and Subtraction – Topic 1.14

Primary KS1 Year 2
Mastery PD Materials

Introduction

Explore counting on, and back, in ten from any two-digit number; apply number facts within ten to the addition and subtraction of multiples of ten.

Teaching points

  • Teaching point 1: When finding ten more or ten less than any two-digit number, the ones digit does not change.
     
  • Teaching point 2: When ten is added or subtracted to/from a two-digit number, the tens digit changes and the ones digit stays the same.
     
  • Teaching point 3: Knowledge of number facts within ten can be applied to adding or subtracting multiples of ten to/from a two-digit number.
     
  • Teaching point 4: Two-digit numbers can be partitioned in different ways.