Calculate $2.40 for 4 ounces or $3.30 for 6 ounces

Step by step

The question

Question: which is the better buy, A: $2.40 for 4 ounces, or B: $3.30 for 6 ounces?

The amounts are different, so we can't just look at the prices.

We find the price for 1 ounce in each deal.

1 Write both as fractions

We write each deal as a fraction.

The money goes on top.

The ounces go on the bottom.

2 Divide to get 1 at the bottom

We want 1 ounce on the bottom.

In A, we divide the top and the bottom by 4.

In B, we divide them by 6.

2.4 divided by 4 is 0.6.

3.3 divided by 6 is 0.55.

So A is 60 cents per ounce.

B is 55 cents per ounce.

3 Compare

55 cents is less than 60 cents.

Deal B costs less for each ounce.

So deal B is the better buy.

Let's look back.

First: write both as fractions.

Then: divide to get 1 at the bottom.

Last: compare.