Maths and numbers

Mental arithmetic, fractions, proportion, combinatorics and olympiad.

15 exercises · 30 progressive levels, from basic to advanced

1. Mental arithmetic

   Sums in your head, from simple ones to multi-step.

2. Hidden operation

   Find which operation is missing from the sum.

3. Mystery number

   Equations and pictures with hidden values.

4. Number pyramid

   Each block is the sum of the two below.

5. Number sequences

   Progressions, squares, Fibonacci and more.

6. Estimation

   Get close to the result without calculating it exactly.

7. Visual fractions

   Fractions with pizzas, bars and problems.

8. Percentages

   Increases, discounts and reverse percentages.

9. Ratio and proportion

   Recipes, maps, speed and proportional sharing.

10. Reverse reasoning

    Find the starting number by undoing the operations.

11. Divisibility

    Rules from 2 to 12.

12. Magic square

    Rows, columns and diagonals with the same sum.

13. Combinatorics

    Count combinations, queues, codes and teams.

14. Probability

    Coins, dice and bags of balls.

15. Olympiad problems

    Classic maths olympiad challenges.