Map scale 1 cm : 5 km, 7 cm on the map

Step by step

The question

Question: with the scale 1 cm : 5 km, how long is 7 cm on the map for real?

The scale means: 1 cm on the map is 5 km for real.

1 Multiply both sides

On the map we have 7 cm.

That is 7 times 1 cm.

So the real length is 7 times 5 km too.

We multiply both sides by the same number, 7.

5 times 7 is 35.

So the real length is 35 km.

2 Check

Let's check: go back.

35 divided by 5 should give the map length, 7.

We get it again.

So 35 km is right!

Let's look back.

First: multiply both sides.

Last: check.