Back through ten

The back-through-ten strategy tends to be more difficult than the up-through-ten strategy because it involves breaking down numbers, as opposed to building them up. However, the same key knowledge of facts to 10 and place value is required. You can watch the Back through Ten video.

 

You can download the Back through Ten video transcript.

 

Back-through-ten strategies can be practised using the learning object L97 The takeaway bar: make your own easy subtractions

 

The problem 24 minus 8 solved by subtracting 4 from 20 and then adding 4, with a diagrammatic representation.

Screen grab from L97 The takeaway bar: make your own easy subtractions.
Source: © Education Service Australia, 2011.

 

These ideas are further explored in Place Value and Number Facts: Addition and Subtraction.

Curriculum links

Year 3: Recall addition facts for single-digit numbers and related subtraction facts to develop increasingly efficient mental strategies for computation

Year 2: Explore the connection between addition and subtraction

Year 2: Solve simple addition and subtraction problems using a range of efficient mental and written strategies

Source