Grabbing 10’s
Activity, Stage 4 – More Mental Math
Turn long addition problems into simpler problems by grouping numbers that add up to 10. Instead of adding 3 + 8 + 9 + 4 + 7 + 6 + 2 from left to right, rearrange the terms to put the number bonds for 10 together. This example becomes (3 + 7) + (8 + 2) + (4 + 6) + 9, which is 10 + 10 + 10 + 9 = 39.
Once this is easy, include trickier problems such as 4 + 8 + 9 + 5 + 3, which can be rearranged as (8 + 9 + 3) + 4 + 5 = 20 + 9 = 29. Make simplifying expressions a game with your child.