Chapter 3 Summary and Review 307To add (or subtract) mixed numbers, we can
also write them in vertical formand add (or
subtract) the whole-number parts and the
fractional parts separately.
When we add mixed numbers, sometimes the
sum of the fractions is an improper fraction. If
that is the case, write the improper fraction as a
mixed number and carryits whole-number part
to the whole-number column.
Add:Build to get the LCD, 21.
Add the fractions.
Add the whole numbers.We don’t want an improper fraction in the answer.
Write as , carry the 1 to the whole-number column, and add it to
131 to get 132:131
25
21
131 1
4
21
132
4
21
(^25211 214)
42
1
3
42
1
3
7
7
42
7
21
4
1
27
21
89
6
7
89
6
7
3
3
89
18
21
89
18
21
25
21
131
25
21
42
1
3
89
6
7
Subtraction of mixed numbers in vertical form
sometimes involves borrowing. When the
fraction we are subtracting is greater than the
fraction we are subtracting it from, borrowing
is necessary.
Subtract:
Build to get the LCD, 36.
Since is greater than , we must
borrow from 28.281
4
28
1
4
9
9
28
9
36
28
7
9
3636
36
28
7
45
36 175
9
17
5
9
4
4
17
20
36
17
20
36
17
20
36
10
25
36
9
3620
36
23
1
4
17
5
9
Add or subtract and simplify, if possible.
101. 102. 39 4
5
8
23
1
3
2
5
6
375
3
4
50 59
5
8
19
1
6
98
11
20
14
4
5
33
8
9
49
1
6
6
3
14
17
7
10
157
11
30
98
7
12
3
7
16
2
1
8
2
5
6
1
3
4
3
1
2
2
2
3
1
3
8
2
1
5
- PAINTING SUPPLIES In a project to restore
a house, painters used gallons of primer,
gallons of latex paint, and gallons of
enamel. Find the total number of gallons of
paint used. - PASSPORTS The required dimensions for a
passport photograph are shown below. What
is the distance from the subject’s eyes to the top
of the photograph?
PASSEPORTPASSPORT
PASAPORTE
USA2 in.2 in.?1 in.^3 – 8(^21 127 23)
(^10 34)
REVIEW EXERCISES