2. Pamela Leutwyler

3. Each set of 10 pebbles must be replaced with 1 pebble in the next pile. Examine the familiar base 10 algorithm. Addition in other bases works the same way. Base 10 pebble board rule:

4. 78 +96 Base 10

5. 78 +96

6. 78 +96

7. 78 +96 Each set of 10 pebbles must be replaced with 1 pebble in the next pile.

8. 78 +96 Base 10 Each set of 10 pebbles must be replaced with 1 pebble in the next pile.

9. 78 +96 4 Base 10 Each set of 10 pebbles must be replaced with 1 pebble in the next pile. 1 Put down 4 Carry 1

10. 78 +96 4 Base 10 Each set of 10 pebbles must be replaced with 1 pebble in the next pile. 1

11. 78 +96 4 Base 10 Each set of 10 pebbles must be replaced with 1 pebble in the next pile. 1

12. 78 +96 4 Base 10 Each set of 10 pebbles must be replaced with 1 pebble in the next pile. 1

13. 78 +96 74 Base 10 Each set of 10 pebbles must be replaced with 1 pebble in the next pile. 1 1

14. 78 +96 174 Base 10 1 1

15. 78 +96 174 1 1

16. Each set of 5 pebbles must be replaced with 1 pebble in the next pile. Base 5 pebble board rule:

17. Base 5 43535 +24545

18. 43535 +24545

19. 43535 +24545

20. Each set of 5 pebbles must be replaced with 1 pebble in the next pile. 43535 +24545

21. Base 5 Each set of 5 pebbles must be replaced with 1 pebble in the next pile. 43535 +24545

22. Base 5 Each set of 5 pebbles must be replaced with 1 pebble in the next pile. 43535 +24545 2 1

23. Base 5 Each set of 5 pebbles must be replaced with 1 pebble in the next pile. 43535 +24545 2 1

24. Base 5 Each set of 5 pebbles must be replaced with 1 pebble in the next pile. 43535 +24545 2 1

25. Base 5 Each set of 5 pebbles must be replaced with 1 pebble in the next pile. 43535 +24545 2 1

26. Base 5 Each set of 5 pebbles must be replaced with 1 pebble in the next pile. 43535 +24545 22 1 1

27. Base 5 Each set of 5 pebbles must be replaced with 1 pebble in the next pile. 43535 +24545 122 1 1

28. Base 5 Each set of 5 pebbles must be replaced with 1 pebble in the next pile. 43535 +24545 122 1 1