Tales of the Unexpected

Tales of the unexpected

When working on mathematical tasks, you may sometimes discover unexpected results that take you by surprise. In this feature, we have chosen some problems that we hope will astonish and amaze you.

The last date for submitting solutions is Friday 18th May. 

Subtraction Surprise 

Stage: 2 and 3 Challenge Level: Challenge Level:1
Try out some calculations. Are you surprised by the results?

Legs Eleven 

Stage: 3 Challenge Level: Challenge Level:2 Challenge Level:2
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?

Angles Inside 

Stage: 3 Challenge Level: Challenge Level:1
Draw some angles inside a rectangle. What do you notice? Can you prove it?

Triangle in a Triangle 

Stage: 4 Challenge Level: Challenge Level:2 Challenge Level:2
Can you work out the fraction of the original triangle that is covered by the inner triangle?

Areas and Ratios 

Stage: 5 Challenge Level: Challenge Level:2 Challenge Level:2
Do you have enough information to work out the area of the shaded quadrilateral?

Another Triangle in a Triangle 

Stage: 5 Challenge Level: Challenge Level:2 Challenge Level:2
Can you work out the fraction of the original triangle that is covered by the green triangle?

Utter Chaos! 

Stage: 4 and 5
A small change can have a big effect! Read all about Chaos Theory in this short article.