The power of ten
Using place value to simplify calculations that are cumbersome with ones is a good way to convince students of the power of the place value system.
Pose addition and subtraction problems -- in context -- that can be solved using place value with no renaming (e.g. 45 + 53 = ? or 127 – 63 = ?).
These problems can be solved using jumping or splitting strategies. Jumping strategies tend to be more reliable as mental strategies whereas splitting strategies are closely related to written algorithms that use place value columns.
You can watch the Splitting Strategies and Jumping Strategies videos.
You can download the Splitting Strategies video transcript.
You can download the Jumping Strategies video transcript.
Jumping strategies can be practised using the empty number line applet on the New Zealand Maths website.