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.

Subtraction Surprise
Age 7 to 14
Challenge Level

Try out some calculations. Are you surprised by the results?

Legs Eleven
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?

Angles Inside
Age 11 to 14
Challenge Level

Draw some angles inside a rectangle. What do you notice? Can you prove it?

Triangle in a Triangle
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 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 18
Challenge Level

Can you work out the fraction of the original triangle that is covered by the green triangle?

Utter Chaos!
Age 14 to 18

A small change can have a big effect! Read all about Chaos Theory in this short article.

Number and algebra

Geometry and measure

Probability and statistics

Working mathematically

Advanced mathematics

For younger learners

Tales of the Unexpected