Math 5.NF.7 Unit fraction

Front

What is a unit fraction?

Back

A unit fraction is a fraction where the numerator is 1 and the denominator is a positive integer, such as 1/2, 1/3, or 1/4.

Front

How do you divide a whole number by a unit fraction?

Back

To divide a whole number by a unit fraction, multiply the whole number by the reciprocal of the unit fraction. For example, 9 ÷ 1/8 is the same as 9 × 8/1 = 72.

Front

What is the reciprocal of a fraction?

Back

The reciprocal of a fraction is obtained by flipping the numerator and denominator. For example, the reciprocal of 1/4 is 4/1.

Front

What is the result of 24 ÷ 1/5?

Back

The result is 120, because 24 ÷ 1/5 is the same as 24 × 5/1.

Front

What does it mean to multiply by a reciprocal?

Back

Multiplying by a reciprocal means to multiply a number by the flipped version of a fraction, which effectively divides the original number by that fraction.

Front

Calculate 6 ÷ 1/2.

Back

The result is 12, because 6 ÷ 1/2 is the same as 6 × 2/1.

Front

What is the result of 9 ÷ 1/3?

Back

The result is 27, because 9 ÷ 1/3 is the same as 9 × 3/1.

Front

If you have 4 ÷ 1/8, what is the answer?

Back

The answer is 32, because 4 ÷ 1/8 is the same as 4 × 8/1.

Front

What is the formula for dividing by a fraction?

Back

The formula for dividing by a fraction is: a ÷ (b/c) = a × (c/b).

Front

Why do we multiply by the reciprocal when dividing by a fraction?

Back

We multiply by the reciprocal to convert the division into multiplication, which is easier to compute.