Surprise!
Curiosity is triggered when something unexpected happens. These problems aim to draw students in by offering that element of surprise.
Subtraction Surprise Age 7 to 14Challenge Level 
Age 7 to 14
Challenge Level
Try out some calculations. Are you surprised by the results?
Angles Inside Age 11 to 14Challenge Level
Age 11 to 14
Challenge Level
Draw some angles inside a rectangle. What do you notice? Can you prove it?
Legs Eleven Age 11 to 14Challenge Level
Age 11 to 14
Challenge Level
Take any four digit number. Move the first digit to the end and move the rest along. Now add your two numbers. Did you get a multiple of 11?
Triangle in a Triangle Age 14 to 16Challenge Level
Age 14 to 16
Challenge Level
Can you work out the fraction of the original triangle that is covered by the inner triangle?
Areas and Ratios Age 16 to 18Challenge Level
Age 16 to 18
Challenge Level
Do you have enough information to work out the area of the shaded quadrilateral?
Another Triangle in a Triangle Age 16 to 18Challenge Level
Age 16 to 18
Challenge Level
Can you work out the fraction of the original triangle that is covered by the green triangle?