To encourage our children to think of doing 9 + 3 as 10 + 2 I have made a set of cards (2 per page) - the big idea that making a friendly number is a good strategy and to stop counting by ones. It also doesn’t matter what the group size is (ie what each dot is worth) eg 90 + 30 = 100 + 20 or what the value of the other digits are eg 39 + 3 = 40 + 2
Some options are to choose to look at the cards which make a friendly 10 (6 + 4, 9 + 1…), or you can keep the number in the frame constant and look at what happens when you add different numbers (9 + 3, 9 + 5, 9 + 7) or look at keeping the number outside the frame constant and the number inside the frame changes (9 + 5, 6 + 5, 7 + 5)
I hope the cards help your students with their being able to picture the numbers they need to add. Thanks C :)
29/01 double of 6 + 9 removed.
17/10 cards with formatting adjusted.