Working systematically

problem

Broken Toaster

Age

7 to 11

Challenge level

Only one side of a two-slice toaster is working. What is the quickest way to toast both sides of three slices of bread?
problem

Bunny Hop

Age

7 to 11

Challenge level

What is the smallest number of jumps needed before the white rabbits and the grey rabbits can continue along their path?
problem

Crack the Code

Age

7 to 11

Challenge level

The Zargoes use almost the same alphabet as English. What does this birthday message say?
problem

Two Dots

Age

7 to 11

Challenge level

Place eight dots on this diagram, so that there are only two dots on each straight line and only two dots on each circle.
problem

Seating Arrangements

Age

7 to 11

Challenge level

Sitting around a table are three girls and three boys. Use the clues to work out were each person is sitting.
problem

Knight's Swap

Age

7 to 11

Challenge level

Swap the stars with the moons, using only knights' moves (as on a chess board). What is the smallest number of moves possible?
problem

Pasta Timing

Age

7 to 11

Challenge level

Nina must cook some pasta for 15 minutes but she only has a 7-minute sand-timer and an 11-minute sand-timer. How can she use these timers to measure exactly 15 minutes?
problem

Fake Gold

Age

7 to 11

Challenge level

A merchant brings four bars of gold to a jeweller. How can the jeweller use the scales just twice to identify the lighter, fake bar?
problem

Tri-Five

Age

7 to 11

Challenge level

Find all the different shapes that can be made by joining five equilateral triangles edge to edge.
problem

A Shapely Network

Age

7 to 11

Challenge level

Your challenge is to find the longest way through the network following this rule. You can start and finish anywhere, and with any shape, as long as you follow the correct order.