Stage: 2 Challenge Level: 
In a square in which the houses are evenly spaced around the outside, numbers $3$ and $10$ are opposite each other.
What is the smallest number of houses in the square?
What is the largest possible number of houses in the square?
Multiplication & division. Visualising. Working systematically. Addition & subtraction. Combinations. Divisibility. Factors and multiples. Counting. Practical Activity. Interactivities.
Published June 2000,November 2009,December 2009.
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