Page 83 - MAT KS3 Y8 Cambridge CheckPoint

7.8 Multiplying and dividing fractions

3 Work these out mentally.
2
3
a 1 ÷ b 1 ÷ c 3 ÷ 4
4 3 2 5 8 7 In parts d, e and f write your
1
2
d 4 ÷ e 3 ÷ f 9 ÷ 1 answer as a mixed number.
5 9 5 11 10 3
4 Work these out mentally.
Cancel each answer to its simplest form.
3
1
1
2
a 3 ÷ b 4 ÷ 3 c 5 ÷ d 4 ÷ e 6 ÷ f 7 ÷ 3
4 2 5 10 6 3 9 3 7 7 8 4
5 Copy this secret code box.
E
1 1 4 1 8 1 1 9 5 7 5 9 1 4
1 1 3 1 3 1
9 6 7 14 9 9 14 22 18 10 18 10 35 7

Work out the answer to each of the questions in the box on the right.
1 × 2 1 × 1
Find the answer in the secret code box, then write the letter from the E 4 3 U 5 7
question box above the answer. L 2 ÷ 3 I 1 ÷ 2
2
For example, the first question is 1 × . 3 4 5 7
4 3 H 3 × 6 S 4 × 5
1
1
1 × 2 = 2 = , so E goes above in the table. 4 11 9 8
4 3 12 6 6 4 8 3 2
F 5 ÷ 9 A 5 ÷ 10
What is the secret message?
6 × 2 5 ÷ 2
N 7 3 T 7 3
8 4
M ÷
9 5

Summary

You should now know that: You should be able to:
★ You can use division to convert a fraction to ★ Find equivalent fractions, decimals and
a decimal by dividing the numerator by the percentages by converting between them.
denominator. ★ Convert a fraction to a decimal using division.
★ To work out a fraction of a quantity, when you ★ Know that a recurring decimal is a fraction.
expect the answer to be a fraction, multiply the
★ Order fractions by writing with common
quantity by the numerator then divide by the
denominators or dividing and converting to
denominator.
decimals.
★ To multiply an integer by a fraction, use the same ★
method as for finding a fraction of a quantity. Add and subtract fractions and mixed numbers.
★ Calculate fractions of quantities with fraction
★ To divide an integer by a fraction, turn the fraction
answers.
upside down and multiply.
★ Multiply and divide an integer by a fraction.
★ To multiply one fraction by another, multiply
the numerators together and multiply the ★ Use the laws of arithmetic to simplify calculations
denominators together. with integers and fractions (cancel).
★ To divide one fraction by another, turn the second ★ Use known facts to multiply and divide simple
fraction upside down and multiply. fractions.

7 Fractions 81