Spinner Maker

Impossible = 0. Certain = 1. Even chance = exactly 1/2. Unlikely = more than 0 but less than 1/2. Likely = more than 1/2 but less than 1.

For equal slices, count the wanted slices out of all the slices. For uneven slices, compare the sizes of the coloured regions.

Equivalent fractions describe the same chance: 1/2, 3/6 and 5/10 are equal.

Experiments can give surprising results. The mathematical chance is what decides the correct answer.

Use − and + for small changes. Use −− and ++ for larger changes. On uneven spinners, you can also drag the boundary handles or use arrow keys when a handle has keyboard focus.

Each correct first attempt earns 100 points, a second attempt earns 75, and using a hint limits the round to 50 points. A fair-game repair can earn a small bonus for few changes.