Chain Sums

Rules

1. A 3-second countdown, then the GO signal.
2. Each sum has three numbers and two operations.
3. Mind the order: multiplication and division come before addition and subtraction.
4. You answer with the 1, 2 and 3 keys or by clicking the answer.
5. You get 1 min 15 s from the signal.

How scoring works

Every right answer scores, more the faster you answer, and every wrong one costs you.

Levels

• Gold level2,300 points
• Silver level1,600 points
• Bronze level900 points

Levels are earned by result; medals are only for the CCI Olympics.

Tips

• Spot the multiplication first and solve it; the rest is a simple sum.
• When in doubt, rule out: the last digit is often enough to tell which one it is not.

Event ranking

See the full ranking