Fraction of a Quantity

Fraction of a Quantity

A fraction of a quantity means taking part of a whole amount. The fraction tells you how many equal parts to take, and the quantity is the total amount.

Method

1. Find the quantity you are working with.
2. Use the fraction to decide how many equal parts the whole is split into.
3. Divide first by the denominator.
4. Multiply by the numerator.

For example, to find (\frac{3}{4}) of 20:

• Divide 20 by 4 to get 5.
• Multiply 5 by 3 to get 15.

So (\frac{3}{4}) of 20 is 15.

Another way

You can also multiply directly: [ \frac{3}{4} \times 20 = 15 ] This is the same idea as “divide by the bottom, multiply by the top.”

Check your answer

• The answer should be smaller than the whole when the fraction is less than 1.
• If the fraction is more than 1, the answer should be larger than the whole.
• You can estimate to see if the result is reasonable.

Tip

If the answer is not a whole number, leave it in exact form when possible, and simplify your fraction if needed.