A row of balance scales, each one perfectly level. On the pans are shapes — circles, triangles, squares, stars and hearts — and sometimes plain weights. Each kind of shape always weighs the same.
Start with scales that have only one kind of unknown shape: two circles balancing 8 kg means a circle is 4 kg. Then put what you know into the other scales. On harder levels you will need to compare two scales: if a triangle and a square balance 9, and a triangle, a square and a star balance 14, the star must weigh 5.
It is algebra in pictures — the same thinking as solving equations, without a single letter.
Every set of scales balances — work out the whole-number weight of each shape.
The full guide, with a worked example and common mistakes: How to play Balance Scales.
Yes — different shapes can have equal weights; only the same shape must always match.
No — every step can be done by looking at the scales, though it is the same thinking.
Yes — every puzzle is checked so that only one set of weights balances every scale.