Working with the person beside you, represent the following on separate fraction strips. (i) 2 ÷ 1
__ 3
(ii) 3·5 ÷ 1
__ 4
(iii) 1
__ 4 ÷ 1
__ 2
The reciprocal of a fraction is the fraction turned upside- down (inverted). For example, 5
__ 2 is the reciprocal of 2
__ 5 .
Dividing fractions by multiplying reciprocals
It may not always be practical to draw fraction strips each time we are dividing fractions, so we can use the steps shown for 1
_ 2 ÷ 3
1
Leave the fi rst fraction as it is. 1
_ 2 ÷ 3
3
_ 4 = ?
_ 4
2
Change the division sign to a multiplication sign and fi nd the reciprocal of the second fraction, by turning it upside-down. 1
_ 2 × 4
_ 3 = ?
Multiply the numerators together to get the numerator of the answer, and multiply the denominators together to get the denominator of the answer. Simplify the answer if necessary.
_ 2 × 4
1 So 1
Worked example Express the following as a single fraction. (i) 4