Upload
marilyn-melton
View
226
Download
7
Tags:
Embed Size (px)
Citation preview
Cancelling fractions to their lowest termsA fraction is said to be expressed in its lowest terms if the numerator and the denominator have no common factors.
Which of these fractions are expressed in their lowest terms?
14
16
20
27
3
13
15
21
14
35
32
15
Fractions which are not shown in their lowest terms can be simplified by cancelling.
7
8
5
7
2
5
Mixed numbers and improper fractionsWhen the numerator of a fraction is larger than the denominator it is called an improper fraction.
For example,
15
4is an improper fraction.
We can write improper fractions as mixed numbers.
15
4can be shown as
15
4= 3
3
4
Improper fraction to mixed numbers
Convert to a mixed number.378
378
=88
+ + +88
88
88
+58
581 + 1 + 1 += 1 +
= 4 5
8437 ÷ 8 = 4 remainder 5 37
8= 4
5
84This is the number of times 8 divides into 37.
4
This number is the remainder.
5
227733
Mixed numbers to improper fractions
Convert to an improper fraction.273
273 =
271 + 1 + 1 +
=77
+ + +77
77
27
=237
To do this in one step,
=
Multiply these numbers together …
… and add this number …
… to get the numerator.237
Finding a fraction of an amount
We can see this in a diagram:
23
of £18 = £18 ÷ 3 × 2 = £12
23
of £18?What is
To find of an amount we need to add 1 times the amount to two fifths of the amount.
251
1 × 3.5 m =3.5 m and2
5of 3.5 m = 1.4 m
so, of 3.5 m =2
51 3.5 m + 1.4 m =4.9 m
What is of 3.5m?2
51
Finding a fraction of an amount
We could also multiply by 7
5
Which is bigger or ?38
512
To compare two fractions convert them to equivalent fractions.
First we need to find the lowest common multiple of 8 and 12.
The lowest common multiple of 8 and 12 is 24.
Now, write and as equivalent fractions over 24. 38
512
38
=24
×3
×3
9and
512
=24
×2
×2
10so,
38
512
<
Using equivalent fractions