A map has a scale of 1 cm to 4 km. Two towns are 6.5 cm apart on the…

Step by step

The question

Question: with the scale 1 cm : 4 km, how long is 6.5 cm on the map in real life?

The scale means: 1 cm on the map is 4 km for real.

1 Multiply both sides

On the map we have 6.5 cm.

That is 6.5 times 1 cm.

So the real length is 6.5 times 4 km too.

If 1 cm is 4 km, then 6.5 cm is 6.5 times as much.

So we multiply both sides, the map side and the real side, by the same number, 6.5.

Forget the points: 4 times 65 is 260.

6.5 is 65 tenths.

So the answer is 260 tenths.

That is 1 digit after the point: 26.0, which is 26.

So the real length is 26 km.

2 Check

Let's check: go back.

26 divided by 4 should give the map length, 6.5.

We get it again.

So 26 km is right!

Let's look back.

First: multiply both sides.

Last: check.