Working systematically

problem
Shapely pairs

Age

11 to 14

Challenge level

A game in which players take it in turns to turn up two cards. If they can draw a triangle which satisfies both properties they win the pair of cards. And a few challenging questions to follow...
problem
Multiply the addition square

Age

11 to 14

Challenge level

If you take a three by three square on a 1-10 addition square and multiply the diagonally opposite numbers together, what is the difference between these products. Why?
problem
Complete the square

Age

5 to 7

Challenge level

Complete the squares - but be warned some are trickier than they look!
problem
Medal ceremony

Age

14 to 16

Challenge level

The teacher has forgotten which pupil won which medal. In how many different ways could he give the medals out to the pupils?
problem
Patchwork quilt

Age

7 to 14

Challenge level

Squares of the type shown are sewn together to make a quilt. How many different quilts can be made?
problem
Three ball line up

Age

5 to 7

Challenge level

Use the interactivity to help get a feel for this problem and to find out all the possible ways the balls could land.
problem
Nine-pin triangles

Age

7 to 11

Challenge level

How many different triangles can you make on a circular pegboard that has nine pegs?
problem
Triangles all around

Age

7 to 11

Challenge level

Can you find all the different triangles on these peg boards, and find their angles?
problem
Right angles

Age

11 to 14

Challenge level

Can you make a right-angled triangle on this peg-board by joining up three points round the edge?
problem
Triangles in circles

Age

11 to 14

Challenge level

Can you find triangles on a 9-point circle? Can you work out their angles?