Year Four children at Furzedown Primary School In Wandsworth used the website to learn how to measure the height of a tree, without having to climb to the top of it!

Working in groups of two or three, they first accurately measured one of the group in the classroom using a metre stick.  Then they went out into the playground.They chose a tree, and got the person who had been measured to stand next to it. Then they walked exactly 10 metres away, and held up a ruler at arms length. They lined the top of the ruler with the person's head, and marked the ruler with a pencil where it lined up with their feet.

Then they estimated how many times the marked length went into the height of the tree. They multiplied the person's height by this number to work out how tall their tree was.