Addition and Subtraction

To know pairs to 20.

Abacus Workbook 1 | 20 counters

sum | total | number pair

Lay out the 20 counters on the table, organised into two rows of 10.

If you do not have access to coloured counters, print out the 📄 Coloured counters resource and cut out the counters.

Show that there are 20 counters on the table.

Write: 20 + 0 = 20.

This is an important idea, that 20 and 0 go together to make 20. Reinforce that this is a similar idea to 10 + 0 = 10.

Ask your student to close their eyes while you hide a counter. Then ask them to open their eyes and tell you how many you have hidden.

Ask them how they worked this out. They may have quickly realised that there is one counter missing from one of the rows of 10.

Record: 19 + 1 = 20.

Repeat this game by hiding other amounts of counters. Ask your student to start recording the number sentences.

This video demonstrates the above game.

Access the link to the Strike it Out game.

This is a game for two players. All the instructions for the game are on the link, including a video demonstration.

Use the 📄 Number lines resource to go with the game.

To help your student consolidate their learning from today, please ask them to complete the activities on page 11 of Abacus Workbook 1.

Citations