Stage: 2 Short Challenge Level: 
On a calculator, make $15$ by using only the $2$ key and any of the operations keys ($+$, $-$, $\times$, $\div$).
How many ways can you find to do it?
Generalising. Addition & subtraction. Calculators. Trial and improvement. Working systematically. Combinations. Investigations. Interactivities. Factors and multiples. Multiplication & division.
Published October 1999.
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