Grade 3’s have been exploring the connection between adding and subtracting. Finding the difference between two numbers can be found by using the ‘jump strategy’.

First we made two numbers using the digits on dice, then we found the position of those numbers on super large number-lines (drawn on the basketball court).

The jump strategy starts at your number then jumps to the next ‘ten number’, then how many tens and finally to the other student’s number. The size of the three jumps is added up.

This total is what you need to add to make the higher number AND what you have to take away to get back to the lower number.

Of course this can all be drawn on a paper number line, but real jumping is so much more fun.

Stephanie van der Schans, AST/Numeracy.