year 8 maths

4A
Equivalent fractions
197
4A Equivalent fractions
REVISION
Fractions are extremely useful in all practical situations whenever a
proportion is required. Fractions are used by a chef measuring the
ingredients for a cake, a builder measuring the ingredients for concrete,
and a musician using computer software to create music.
A fraction is formed when a whole number or amount is divided into
equal parts. The bottom number is referred to as the denominator (down)
and tells you how many parts the whole is divided up into. The top number
is referred to as the numerator (up) and tells you how many of the parts
you have selected.
4 parts selected
Numerator
Denominator
4
7
The whole is divided into 7 parts.
Equivalent fractions are fractions that represent equal portions of a whole amount and so are equal in
value. The skill of generating equivalent fractions is needed whenever you add or subtract fractions with
different denominators.
Let’s start: Know your terminology
It is important to know and understand key terms associated with the study of fractions.
Working with a partner and using your previous knowledge of fractions, write a one-sentence definition or
explanation for each of the following key terms. Also give an example of each.
• numerator
• equivalent fraction
• improper fraction
• multiples
• reciprocal
• lowest common multiple
• ascending
• composite number
• denominator
• proper fraction
• mixed numeral
• factors
• highest common factor
• descending
• lowest common denominator
• rational numbers
• irrational numbers
■ Equivalent fractions are equal in value. They mark the same place on a number line.
For example, 3 5 and 6
are equivalent fractions.
10
0
5
1
5
2
5
0 1 2 3 4 5 6 7 8 9 1
10 10 10 10 10 10 10 10 10
3
5
4
5
5
5
Key ideas
Cambridge Maths NSW
Stage 4 Year 8 Second edition
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
Photocopying is restricted under law and this material must not be transferred to another party.