274 Chapter 3 Fractions and Mixed Numbers
Self Check 4Add:Now TryProblem 2571
5
8
23
1
3
EXAMPLE 4
Add:
StrategyWe will perform the addition in vertical formwith the fractions in a
column and the whole numbers lined up in columns. Then we will add the fractional
parts and the whole-number parts separately.
WHY It is often easier to add the fractional parts and the whole-number parts of
mixed numbers vertically—especially if the whole-number parts contain two or
more digits, such as 25 and 31.
Solution
Write the mixed numbers in vertical form.
Build and so that their denominators are 20.
Add the fractions separately.
Add the whole numbers
separately.The sum is 56.19
20
25
15
20
31
4
20
56
19
20
25
15
20
31
4
20
19
20
25
3
4
5
5
31
1
5
4
4
25
3
4
31
1
5
1
53
425
3
4
31
1
5
EXAMPLE 5
Add and simplify, if possible:StrategyWe will write the problem in vertical form. We will make sure that the
fractional part of the answer is in simplest form.
WHY When adding, subtracting, multiplying, or dividing fractions or mixed
numbers, the answer should always be written in simplest form.
SolutionThe LCD for , , and is 12.Write the mixed numbers in vertical form.
Build and so that their denominators are 12.
Add the fractions separately.
Add the whole numbers
separately.The sum is 172.1
2
75
(^1 1 1)
12
43
3
12
54
2
12
172
6
12
172
1
2
75
1
12
43
3
12
54
2
12
6
1275
1
12
43
1
4
3
3
54
1
6
2
2
75
1
12
43
1
4
54
1
6
1
61
41
6
1
4
1
12
75
1
12
43
1
4
54
1
6
Self Check 5
Add and simplify, if possible:Now TryProblem 2968
1
6
37
5
18
52
1
9
Simplify:126 ^6.1
2 61 1
2