Stage: 3 Challenge Level: 
You might find it helpful to start by taking a look at the Level 1 and 2 problems in Shifting Times Tables.
Factors and multiples. Generalising. smartphone. Modulus arithmetic. Mental calculation strategies. Visualising. Multiplication & division. Mental multiplication & division. Creating expressions/formulae. Divisibility.
Published November 2009,December 2009,November 2011,December 2011.
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