Algorithms: column addition

Spine 1: Number, Addition and Subtraction – Topic 1.20

Primary Year 3 KS2
Mastery PD Materials

Introduction

Introduce children to the column algorithm for addition calculations, applying the algorithm to a variety of aggregation and augmentation contexts for two-digit and three-digit numbers; explore regrouping (column total is ten or greater) in detail.

Teaching points

  • Teaching point 1: Any numbers can be added together using an algorithm called ‘column addition’.
     
  • Teaching point 2: The digits of the addends must be aligned correctly before the algorithm is applied.
     
  • Teaching point 3: In column addition, the digits of the addends are added working from the least significant digit (on the right) to the most significant digit (on the left).
     
  • Teaching point 4: If any column sums to ten or greater, we must ‘regroup’.
     
  • Teaching point 5: The numbers within each column should be added in the most efficient order.