A circle with the radius of 2.2 centimetres is drawn touching the sides of a square. What area of the square is NOT covered by the circle?

Practice your skills of measurement and estimation using this interactive measurement tool based around fascinating images from biology.

At the time of writing the hour and minute hands of my clock are at right angles. How long will it be before they are at right angles again?

Can you choose your units so that a cube has the same numerical value for it volume, surface area and total edge length?

Scientist Bryan Rickett has a vision of the future - and it is one in which self-parking cars prowl the tarmac plains, hunting down suitable parking spots and manoeuvring elegantly into them.

My measurements have got all jumbled up! Swap them around and see if you can find a combination where every measurement is valid.

A white cross is placed symmetrically in a red disc with the central square of side length sqrt 2 and the arms of the cross of length 1 unit. What is the area of the disc still showing?

Examine these estimates. Do they sound about right?

Making a scale model of the solar system

My recipe is for 12 cakes - how do I change it if I want to make a different number of cakes?

Design and test a paper helicopter. What is the best design?

Mathematics has always been a powerful tool for studying, measuring and calculating the movements of the planets, and this article gives several examples.

From the measurements and the clue given find the area of the square that is not covered by the triangle and the circle.