5-8 Adding and Subtracting Mixed Numbers
Learn to add and subtract mixed numbers
with unlike denominators.
Course 1
5-8 Adding and Subtracting Mixed Numbers
Additional Example 1A: Adding and Subtracting
Mixed Numbers
Find the sum. Write the answer in simplest form.
1
8
5
6
A. 3 __ + 1 __
1
3 __
8
5
+1 __
6
______
6
3 __
48
40
+ 1 __
48
______
46
23
4 __ = 4 __
48
24
Course 1
Multiply the denominators.
8 · 6 = 48
Write equivalent fractions
with a denominator of 48.
Add the fractions and then
whole numbers, and simplify.
5-8 Adding and Subtracting Mixed Numbers
Additional Example 1B: Adding and Subtracting
Mixed Numbers
Find the difference. Write the answer in simplest form.
2
3
1
4
B. 5 __ – 1 __
2
5 __
3
1
–1 __
4
______
Course 1
8
5 __
12
3
– 1 __
12
______
Write equivalent fractions
with a denominator of 12.
5
4 __
12
Subtract the fractions and
then the whole numbers.
The LCD of the denominators is 12.
5-8 Adding and Subtracting Mixed Numbers
Additional Example 1D: Adding and Subtracting
Mixed Numbers
Find the difference. Write the answer in simplest form.
2
3
2
9
D. 6 __ – 3 __
2
6 __
3
2
–3 __
9
______
6
6 __
9
2
– 3 __
9
______
4
3 __
9
Course 1
Think: 9 is a multiple of 3, so 9
is the LCD.
Write equivalent fractions
with a denominator of 9.
Subtract the fractions and
then the whole numbers.
5-8 Adding and Subtracting Mixed Numbers
Additional Example 1C: Adding and Subtracting
Mixed Numbers
Find the sum. Write the answer in simplest form.
1
4
C. 2 __ + 4 __
2
1
2 __
2
4
+4 __
5
______
5
5
2 __
10
8
+ 4 __
10
______
13
3
6 __ = 7 __
10
10
The LCD of the denominators
is 10.
Write equivalent fractions
with a denominator of 10.
Add the fractions and then
the whole numbers.
13
3
6 __ = 6 + 1 __
10
10
Course 1
5-8 Adding and Subtracting Mixed Numbers
Lesson Quiz
Find each sum or difference. Write the answer in
simplest form.
1
__
2
__ – 4 __
1. 7 11
3
__
1 + 7__
3 16 13
2. 9 __
7
__
2 – 4 __
1
4. 10 __
6
12
3
6
4
__
7
3
3. 6 __
+ 1 __
8
8
10
40
24
8
7
5
6
30
3
2 hours on
5. Miles worked 5 __ hours on Friday and 8 __
4
3
Saturday. How many total hours did he work?
5
14 __ hours
12
Course 1