Addition and Subtraction

Objectives

To add pairs of 2-digit numbers by partitioning.

Resources

Abacus Workbook 2 | Interactive Place Value (Mathsframe) | 📄 Adding 2-digit numbers

Vocabulary

adding | addition | partition

Today's Lesson

Introduction

Ask: ‘When we learnt to double numbers like 34, what did we do? Could we use this method to add 34 and 23?’

Ask your student to use the Interactive Place Value website to make the two numbers 34 and 23.

EXPLORE - Interactive Place Value (Mathsframe)

Ask: ‘What is the total of the 10s? And the total of the 1s? How much altogether?’

Record:

34 + 23

= 30 + 20 + 4 + 3

= 50 + 7

= 57

Repeat for 45 + 24, 36 + 22 and then 46 + 25.

For the latter, record the partitioning as above. Highlight that this time the ones cards came to more than 10, so we can record as:

46 + 25

= 40 + 20 + 6 + 5

= 60 + 11

= 71

This video will demonstrate using the place value cards on Mathsframe to help add together 2-digit numbers.

Main Activity

Ask your student to complete the additions on 📄 Adding 2-digit numbers, using the Interactive Place Value resource as necessary to support their thinking.

EXPLORE - Interactive Place Value (Mathsframe)

It is important that they get into the habit of recording their working out as in the Introduction.

Workbook

To help your student consolidate their learning from today, please ask them to complete the activities on page 21 of Abacus Workbook 2.

Citations

[1] mathsframe.co.uk