Calculation by Color

? How to play

The COLOUR of the numbers rules, not the sign between them. Check the key at the top, apply that colour's operation and choose the result.

1. The key at the top shows which operation goes with each colour.
2. Look at the colour of the numbers: that, and only that, decides whether you add, subtract or multiply.
3. The sign printed between the numbers sometimes matches the colour and sometimes it doesn't. When it doesn't, ignore it: that's the trick of the exercise.
4. Choose the result, or use Block if you prefer to cut the round short.