A. Quick Addition
Do these problems in your head. Write only the answers.
- 4 + 9 =

- 40 + 90 =

- 20 + 90 =

- 20 + 30 =

- 30 + 50 =

- 40 + 60 =

- 10 + 90 =

- 60 + 80 =

- 80 + 70 =

- Show or tell your strategy for Problem I.











