Scale and maps

Hello, and welcome to Myriora Maths! On a map, two towns are four centimetres apart. But in real life, they're much further apart than that! The map's scale tells us how far. Let's see how.

This map has a scale of one to twenty-five thousand. That means one centimetre on the map is twenty-five thousand centimetres in real life.

That's a lot of centimetres! A hundred centimetres make a metre, so twenty-five thousand centimetres is two hundred and fifty metres. So every centimetre on the map is two hundred and fifty metres on the ground.

The towns are four centimetres apart on the map. Four times two hundred and fifty metres is a thousand metres. That's one kilometre!

Scales are used for models too. A toy car with a scale of one to forty is forty times smaller than the real car. If the toy is ten centimetres long, the real car is four hundred centimetres: four metres!

Let's try one together. On a map, one centimetre is two kilometres. Two towns are three centimetres apart. How far apart are they really? Say it out loud!

Three times two kilometres is six kilometres!

Here's a question that catches lots of people. A map has a scale of one to fifty thousand. Two places are two centimetres apart on the map. Some people say a hundred thousand metres. But the scale is in centimetres! A hundred thousand centimetres is a thousand metres: one kilometre.

Your turn! A map has a scale of one to ten thousand. A path on the map is six centimetres long. How long is it in real life? Pick the right card. You've got twenty seconds, or pause the video. Go!

Time's up! Six times ten thousand is sixty thousand centimetres. Divide by a hundred to get metres: six hundred metres!

Quick review. A scale of one to twenty-five thousand means one unit on the map is twenty-five thousand of the same unit in real life. Multiply the map distance by the scale. Then change the units: a hundred centimetres make a metre, and a thousand metres make a kilometre. Scales work for models too. See you next time!