![Reaction timer](/sites/default/files/styles/medium/public/thumbnails/content-id-6044-icon.png?itok=EGmCGgof)
problem
Reaction timer
This problem offers you two ways to test reactions - use them to investigate your ideas about speeds of reaction.
![Keep it simple](/sites/default/files/styles/medium/public/thumbnails/keep-it-simple.gif?itok=xXs1GgR6)
![How would you score it?](/sites/default/files/styles/medium/public/thumbnails/content-id-6957-icon.png?itok=nYlVH8au)
![Sociable Cards](/sites/default/files/styles/medium/public/thumbnails/content-id-7219-icon.png?itok=6vX4n8lR)
problem
Sociable Cards
Move your counters through this snake of cards and see how far you can go. Are you surprised by where you end up?
![American Billions](/sites/default/files/styles/medium/public/thumbnails/content-01-09-six5-icon.png?itok=jytZpqxV)
problem
American Billions
Play the divisibility game to create numbers in which the first two digits make a number divisible by 2, the first three digits make a number divisible by 3...
![Olympic Records](/sites/default/files/styles/medium/public/thumbnails/content-id-7489-icon.jpg?itok=FVH5AjGC)
problem
Olympic Records
Can you deduce which Olympic athletics events are represented by the graphs?
![Place your orders](/sites/default/files/styles/medium/public/thumbnails/content-id-7500-icon.gif?itok=JIvIbNSv)
problem
Place your orders
Can you rank these sets of quantities in order, from smallest to largest? Can you provide convincing evidence for your rankings?
![Constructing Triangles](/sites/default/files/styles/medium/public/thumbnails/content-id-8098-icon.png?itok=2JGN3wZM)
problem
Constructing Triangles
Generate three random numbers to determine the side lengths of a triangle. What triangles can you draw?
![Fence it](/sites/default/files/styles/medium/public/thumbnails/content-id-2663-icon.png?itok=2LcsRSen)
problem
Fence it
If you have only 40 metres of fencing available, what is the maximum area of land you can fence off?
![Olympic Measures](/sites/default/files/styles/medium/public/thumbnails/content-id-8318-icon.png?itok=K-j1ORoN)
problem
Olympic Measures
These Olympic quantities have been jumbled up! Can you put them back together again?
![Isosceles Triangles](/sites/default/files/styles/medium/public/thumbnails/content-id-2666-icon.png?itok=wmpakUQq)
problem
Isosceles Triangles
Draw some isosceles triangles with an area of $9$cm$^2$ and a vertex at (20,20). If all the vertices must have whole number coordinates, how many is it possible to draw?
![All in a jumble](/sites/default/files/styles/medium/public/thumbnails/content-id-5994-icon.png?itok=sVnQZK_y)
problem
All in a jumble
My measurements have got all jumbled up! Swap them around and see
if you can find a combination where every measurement is valid.
![Power mad!](/sites/default/files/styles/medium/public/thumbnails/content-id-6401-icon.png?itok=Ukk2Xjef)
problem
Power mad!
Powers of numbers behave in surprising ways. Take a look at some of these and try to explain why they are true.
![Who's the best?](/sites/default/files/styles/medium/public/thumbnails/content-id-7367-icon.png?itok=-3MEzqSp)
![Coordinate Patterns](/sites/default/files/styles/medium/public/thumbnails/content-id-2292-icon.png?itok=tWsgfytK)
problem
Coordinate Patterns
Charlie and Alison have been drawing patterns on coordinate grids. Can you picture where the patterns lead?
![Peaches today, Peaches tomorrow...](/sites/default/files/styles/medium/public/thumbnails/content-id-2312-icon.png?itok=QobLRChL)
problem
Peaches today, Peaches tomorrow...
A monkey with peaches, keeps a fraction of them each day, gives the rest away, and then eats one. How long can his peaches last?
![Rhombus It](/sites/default/files/styles/medium/public/thumbnails/content-id-15165-icon.png?itok=1iXhLMGD)
problem
Rhombus It
Players take it in turns to choose a dot on the grid. The winner is the first to have four dots that can be joined to form a rhombus.
![Shapely pairs](/sites/default/files/styles/medium/public/thumbnails/content-id-2925-icon.png?itok=TRGXNBMk)
problem
Shapely pairs
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...
![Property chart](/sites/default/files/styles/medium/public/thumbnails/content-id-2927-icon.png?itok=oTWSefvP)
problem
Property chart
A game in which players take it in turns to try to draw
quadrilaterals (or triangles) with particular properties. Is it
possible to fill the game grid?
![Route to infinity](/sites/default/files/styles/medium/public/thumbnails/content-id-5469-icon.png?itok=277vYUz4)
problem
Route to infinity
Can you describe this route to infinity? Where will the arrows take you next?
![Method in multiplying madness?](/sites/default/files/styles/medium/public/thumbnails/content-id-5612-icon.png?itok=ZHpntMLH)
problem
Method in multiplying madness?
Watch our videos of multiplication methods that you may not have met before. Can you make sense of them?