Stage: 1 Challenge Level: 
Can you place the numbers from $1$ to $10$ in the grid (or matrix) below?
Now try putting the same numbers in this grid:
Investigations. Odd and even numbers. Addition & subtraction. Generalising. Interactivities. Prime numbers. Trial and improvement. Factors and multiples. Multiplication & division. Working systematically.
Published March 2005,April 2005.
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