1. Draw it! (draw a representation of the situation)
2. Make a systematic list.
3. Elimination
4. Reason with a matrix
5. Find a pattern (Criteria B)
6. Trial and error
7. Divide the problem in subproblems
8. Solve an easier version of the problem (or 'Use easy numbers')
9. DO the problem.
10. Work backwards
11. Use Venn-diagrams
12. Use algebraic methods
13. Present the information differently
14. Change your perspective
15. Use (other) graphic methods
16. Use specific materials