Prime numbers

This group tasks allows you to search for arithmetic progressions in the prime numbers. How many of the challenges will you discover for yourself?

The flow chart requires two numbers, M and N. Select several values for M and try to establish what the flow chart does.

Show that it is rare for a ratio of ratios to be rational.

Using your knowledge of the properties of numbers, can you fill all the squares on the board?

Take any pair of numbers, say 9 and 14. Take the larger number, fourteen, and count up in 14s. Then divide each of those values by the 9, and look at the remainders.

Use cubes to continue making the numbers from 7 to 20. Are they sticks, rectangles or squares?

Weekly Problem 24 - 2006
How many of the rearrangements of the digits 1, 3 and 5 give prime numbers?

Can you make lines of Cuisenaire rods that differ by 1?