12 of 40 students walk to school. About how many of 600 walk?

Step by step

The question

Question: 12 of 40 students walk to school.

About how many of 600 walk?

1 The fraction in the sample

12 out of 40: that is 12/40.

The 40 students are a sample: a small group that stands for everyone.

12 and 40 can both be divided by 4.

So it is 3/10.

2 Use it for everyone

We expect the same fraction of all 600: 3/10 of 600.

Of means times.

600 divided by 10 is 60.

Then times 3.

That is about 180.

Careful!

A sample only shows about how many.

So the answer is a good guess, not an exact count.

So about 180 students walk.

3 Check

Let's check: 180 out of 600.

Divide the top and the bottom by 60: 3/10, the same fraction as the sample.

So the answer is right!

Let's look back.

First: the fraction in the sample.

Then: use it for everyone.

Last: check.