3.03 Addition strategies

Start with the bigger number and count to the right by the smaller number.

Locate where 43 is on the number line. We can find 43 + 12 by jumping from 43 to the right by 12:

So, 43 + 12 = 55

Use the bridge to 10 strategy.

In the picture, we have 9 squares shaded. We need 1 more square to complete the pair to 10 squares.

So the bridge is 1. So we need to add 1 to get to 10:

9 + 1 = 10

Use the compensation strategy.

If we look at 7 + 10 and 7 + 11, we can see that 10 has been changed to 11.

11 is 1 more than 10 as shown on the number line.

So we need to add 1 more to 7+10=17. To add 1 to 17 we can use a number line and find 17 and move 1 place to the right to get 18:

So, 7 + 11 = 18