Stage: 1 Challenge Level: 
If a $2$ balances with two $1$s and a $3$ balances with three $1$s, can you see how the balance works?
Have you tried out some ideas on the interactivity?
Visualising. Addition & subtraction. Combinations. Games. Trial and improvement. Multiplication & division. Working systematically. Interactivities. Mass and weight. Comparing and Ordering numbers.
Published January 2006.
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