Working systematically

problem

Penta Primes

Age

7 to 11

Challenge level

3 out of 3

Using all ten cards from 0 to 9, rearrange them to make five prime numbers. Can you find any other ways of doing it?
problem

Counters

Age

7 to 11

Challenge level

3 out of 3

Hover your mouse over the counters to see which ones will be removed. Click to remove them. The winner is the last one to remove a counter. How you can make sure you win?
problem

Uncanny Triangles

Age

7 to 11

Challenge level

3 out of 3

Can you help the children find the two triangles which have the lengths of two sides numerically equal to their areas?
problem

Seven Flipped

Age

7 to 11

Challenge level

3 out of 3

Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
problem

Cuboid-In-A-Box

Age

7 to 11

Challenge level

3 out of 3

What is the smallest cuboid that you can put in this box so that you cannot fit another that's the same into it?
problem

Sticks and Triangles

Age

7 to 11

Challenge level

3 out of 3

Using different numbers of sticks, how many different triangles are you able to make? Can you make any rules about the numbers of sticks that make the most triangles?
problem

More and More Buckets

Age

7 to 11

Challenge level

3 out of 3

In this challenge, buckets come in five different sizes. If you choose some buckets, can you investigate the different ways in which they can be filled?
problem

Three Sets of Cubes, Two Surfaces

Age

7 to 11

Challenge level

3 out of 3

How many models can you find which obey these rules?
problem

Building With Rods

Age

7 to 11

Challenge level

3 out of 3

In how many ways can you stack these rods, following the rules?
problem

Crossing the Town Square

Age

7 to 11

Challenge level

3 out of 3

This tricky challenge asks you to find ways of going across rectangles, going through exactly ten squares.