Subtraction facts

This task is about using an algorithm to calculate subtraction problems.
Write your answers in the boxes.
You can use the remaining area to do your working.
 

1

  17

-   9

equals area

2.

  74

- 21

equals area

3.

  52

- 37

equals area

4.

  775

- 432

equals area

5.

  536

- 277

equals area

6.

  400

- 126

equals area

7.

  7146

- 5438

equals area