Page 13 - SM inner class 7.cdr

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Chapter2 6 ½ –

Fractions

What is a Fraction 3. Mixed Fractions
When an object is di vided into a number of Mixed fractions have a whole num ber plus a
parts then each part is called a frac tion. frac tion part,
1 19
There are different ways of writing a fraction. For ex am ple : 2 or 123
For ex am ple, two fifths of an object can be 5 20
writ ten as : Equiv a lent frac tions
2 These are different fractions that represent
† a common fraction
5 the same number.
1 2 3 4
† a decimal 0.4 The fractions , , and are equivalent
2 4 6 8
† a percentage 40%
since each represents the same number.
Now let us have a closer look at the common 1 1 2 2 1 3 3 1 4 4
´
2 as: = = ; ´ = ; ´ =
fraction: 2 2 ´ 2 4 2 3 6 2 4 8
5
Nu mer a tor says how many parts in the Both the numerator and denominator of one
frac tion. fraction have been multiplied by the same
number, and those products are the numerator
Vinculum = “divide by”
and denominator of the equivalent fraction.
De nom i na tor says how many equal parts is 1 2 3 4
the whole ob ject di vided. So, , , and are equivalent fractions.
2 4 6 8
Al ways re mem ber : de nom i na tor can never
be 0. 2. Like Fractions
Why? Because you cannot divide any number Fractions with the same denominators
by 0. (bottom numbers) are called like fractions.
Fraction Types For ex am ple :
2 5 12 31
There are 3 different types of fractions: , , and are like fractions with the
13 13 13 13
1. Proper Frac tions :
same denominators (bottom numbers).
Nu mer a tor < De nom i na tor
Proper fractions have the numerator part 3. Unlike Fractions
smaller than the de nom i na tor part, Fractions with different denominators are
1 2 19 called unlike fractions.
for ex am ple, , or
2 5 20 For ex am ple :
2.Im proper Frac tions 2 5 12 and 35 are unlike fractions with
,
,
Nu mer a tor > De nom i na tor or 3 13 17 19
Nu mer a tor = De nom i na tor different denominators .
Improper fractions have the numerator part Converting Fractions into Like
greater or equal to the de nom i na tor part, Fractions
5 7
for ex am ple, or . 4 3
5 2 Convert and into like-fractions.
5 2
4 3
As both and are unlike fractions,
5 2

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Mathematics In Focus - 7