Stage: 3 Challenge Level: 
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What can you say about the values of n that make 7 n + 3 n a multiple of 10?
Are there other pairs of integers between 1 and 10 which have similar properties?
Properties of numbers. Small software. Powers & roots. Index notation/Indices. Visualising. Interactivities. Permutations. Patterned numbers. Factors and multiples. Divisibility.
Published June 2002.
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