Nothing Special   »   [go: up one dir, main page]

Fractions II and Decimals: Mixed Numbers

Download as doc, pdf, or txt
Download as doc, pdf, or txt
You are on page 1of 6

Fractions II and Decimals

By Muralee.V.

Mixed Numbers
The values of mixed numbers can be compared in two ways:
a. A mixed number with the largest whole number has the largest value.
b. If mixed numbers have the same whole number, then do comparison with their
fraction values.
Example 1
State the largest mixed number for each of the following.
1 1
a. 5 and 6
4 7
1 2
b. 7 and 7
4 5

Solution
1 1
a. 5 and 6
4 7
Compare the whole numbers

1 1
Therefore, 5 < 6
4 7
1 2
b. 8 and 8
4 5
Same whole number
5 8
8 and 8
20 20
Change the fractions into its equivalent
with their common denominator
1 2
Therefore, 8 < 8
4 5

Proper Fractions and Improper Fractions

A proper fraction has a bigger denominator than its numerator.


Example
5 Smaller numerator
6
Bigger denominator

An improper fraction has a smaller or equal denominator than its numerator.


Example
8 Bigger numerator
3
Smaller denominator
Equal numerator
38
38
Equal denominator
A mixed number can be changed into an improper fraction by following these steps:
I. Multiply the whole number with denominator;
II. Then, add the product to the numerator;
III. Leave the denominator unchanged.
Example

II
3 (5 7) 3
7 =
5
I
5
35 3
=
5
38
=
5

An improper fraction can be changed into a mixed number by following these steps:
I. Divide the numerator with the denominator
II. Leave the denominator unchanged.
III. The obtained quotient becomes the whole number.
IV. The remainder becomes the numerator

Example

15 Quotient
3 47
47 2 3
= 15 17
3 3 15
Denominator 2 Remainder

Addition and Subtraction of Fractions and Mixed Numbers


1. Addition or subtraction of fractions with a common denominator can be done by
adding or subtracting the numerator only.


2. The denominator remains unchanged
3. If possible, simplify the answer to its lowest term.

Example 2
Solve the following
3 7
a)
11 11
1 5
b)
18 18

Solution
3 7 37
a) =
11 11 11
10
=
11

1 5 1 5
b) =
18 18 18
6
=
18
1
=
3
4. Addition or subtraction of fractions with different denominators can be done by
changing each fraction into its equivalent with a common denominator.
5. Then, add or subtract the numerator only
6. If possible, simplify the answer to its lowest term.

Example 3
Solve the following
4 2
a)
13 39
2 4
b)
3 7

Solution
4 2 43 2
a) =
13 39 13 3 39
12 2
=
39 39
14
=
39
2 4 27 43
b) = 3 7 73
3 7
14 12
=
21 21
2
=
21

7. Addition or subtraction of fractions, whole numbers and mixed numbers.

Example 4
4
a) 5
9
5 3
b) 3
6 5

Solution
4 4
a) 5 = 4 1
9 9
9 4
=4
9 9
5
=4
9

5 3 55 36
b) 3 =3+
6 5 65 56
25 18
=3+
30 30
43
=3+
30

13
=3+1
30
13
=4
30

Multiplication and Division of Fractions


1. In multiplication:
I. Multiply numerator by numerator
II. Multiply denominator by denominator
III. If possible, simplify the answer to its lowest term.
* method of cancellation can be used
Example 5
3 25 75
a) =
5 27 135
5
=
9
or
1 5
3 25 5
= method of cancellation
1 5 927 9

2. In division:
I. Multiply the fraction with the reciprocal of the second fraction
(reciprocal of a number or fraction refers to the inverse of the number or
fraction)
Example
1
3 reciprocal
3
3 reciprocal 14
14 3
II. If possible, simplify the answer to its lowest term.
* method of cancellation can be used

Example 6
2 8 2 49 reciprocal
a) =
7 49 7 8
1 7
2 49
=
7 8
1 4

7
=
4
3
=1
4

3. In multiplication or division of a mixed number by a mixed number:


I. Change the mixed numbers into improper fractions
II. Then, carry out the computations.
III. If possible, simplify the answer to its lowest term.
* method of cancellation can be used

Example 6 1 7

1 2
3 3 8 35
a) 1 2 = Change to
5 16 5 16
improper fraction
7
=
2
1
=3
2

Decimals

Place Tens Ones . Tenths Hundreth Thousanth


Values s s
Digits 6 6 Decimal 3 2 1
Digit 60 6 Point 0.3 0.02 0.001
Values

Test Yourself

4 8
1) 2 2
7 14
2 1 1
2) 1
24 4 2
3) 0.89 x 2.7
8
4) 27 x 1.07
10

Answers
1) 1
1
2)
16
3) 2.403
4) 26.144

You might also like