1. You’ve used the “friendly number” 10 to help solve some math problems.

2. Today you will need….. A pencil Your math journal A hundred’s chart

3. Karen’s calculator broke when she dropped it down the stairs.

4. Karen’s calculator broke when she dropped it down the stairs. On her math homework she had the problem 99 + 8.

5. Karen’s calculator broke when she dropped it down the stairs. On her math homework she had the problem 99 + 8. Karen doesn’t think that she can solve the problem without her calculator.

6. Karen’s calculator broke when she dropped it down the stairs. On her math homework she had the problem 99 + 8. Karen doesn’t think that she can solve the problem without her calculator. Can you suggest a way for her to think about the problem so that she can solve it without her calculator?

7. Share your ideas with a partner. Then we will take a look a way she might be able to think about this problem.

8. Discuss with a partner how 10 can help solve the problems below: 8 + 4 9 + 3 8 + 3

9. Think, Pair, Share How could the number 100 help you solve some problems?

10. It is important to be able to tell how far a number is from 100. A hundreds chart can help you.

11. How far is 99 from 100? 12345678910 11121314151617181920 21222324252627282930 31323334353637383940 41424344454647484950 51525354555657585960 61626364656667686970 71727374757677787980 81828384858687888990 919293949596979899

12. So…what might be the solution to 99 + 8? 12345678910 11121314151617181920 21222324252627282930 31323334353637383940 41424344454647484950 51525354555657585960 61626364656667686970 71727374757677787980 81828384858687888990 919293949596979899

13. How could make 10 and some more help you with this problem? 12345678910 11121314151617181920 21222324252627282930 31323334353637383940 41424344454647484950 51525354555657585960 61626364656667686970 71727374757677787980 81828384858687888990 919293949596979899 18423756 Think 99 +8 is the same as

14. Make ten and some more is also like make a hundred and some more. 12345678910 11121314151617181920 21222324252627282930 31323334353637383940 41424344454647484950 51525354555657585960 61626364656667686970 71727374757677787980 81828384858687888990 919293949596979899100 1423756 Think 99 +8 is the same as 100 + 7

15. How far is 95 from 100? Use your hundreds chart if you would like. Discuss how this could this help you solve the problem 95 + 6?

16. How far is 97 from 100? Use your hundreds chart if you would like. Discuss how this could this help you solve the problem 97 + 4?

17. 10 and 100 are not the only “friendly numbers”.

18. Can you think of ways you can use other “friendly numbers” to help solve the problems below? 19 + 5 3 + 48 39 + 4

19. Write two addition problems that would make use of the friendly numbers below? 602070 408050