Stage: 2 Challenge Level: 
There is just a need to be systematic here. Try taking the information in a different order, starting with facts that have the least number of possibilities. For example the fact about number plates with M only has two possible outcomes.
Practical Activity. Working systematically. Factors and multiples. Addition & subtraction. Combinatorics. Interactivities. Visualising. Multiplication & division. Combinations. Investigations.
Published May 2002.
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