The picture on the right shows Tyler standing next to a tree. Several things about this picture make it possible to estimate this tree's height:

1. The picture includes the top of the tree and the bottom, so you can measure it on your computer screen.
2. Tyler is standing at the base of the tree, right next to it, so his feet start at the same place as the base of the tree.
3. We know what Tyler's real height is. Tyler was132 cm tall when we took this picture.

Let's say you hold your ruler up to this picture on your computer screen and measure Tyler and measure the tree. On the picture, Tyler is 2 cm and the tree is 10 cm.

Now divide the tree height by Tyler's height:

10 divided by 2 equals 5.0. This means that the tree is 5.0 times taller than Tyler.

So, if Tyler is 132 cm tall:     132cm x 5.0 = 660 cm

Our estimate of the tree height is 660 cm tall! Wasn't that easy?

Now, you try some of these problems yourself!