Stage: 2 Challenge Level: 
Starting with the number 180, take away 9 again and again, joining up the dots as you go.
Watch out - don't join all the dots!
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Compound transformations. Trial and improvement. Addition & subtraction. Games. Working systematically. Multiplication & division. Factors and multiples. Visualising. Interactivities. Practical Activity.
Published February 2002.
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