LESSON 16.5
Name
Use the Least Common Denominator
Find the LCD. Then add or subtract.
1
2
2
8
LCD 8; 3
4
1. 2 1
5 3
LCD 15; 1
1
15
2. 6
8
1
4
LCD 8; 1
3. 2
9
12 4
LCD 12; 1
4
4. Find the sum or difference. Write it in simplest form.
2
8
1
4
8
16
5. 3
8
1
4
9. 2
10
3
5
4
5
7. 6
12
2
6
1
6
11. 4
5
1
10
9
10
15. 1
3
2
9
1
9
19. 6. 10. 1
8
5
8
5
16
1
5
16
2
20
4
5
9
10
13. 17. 14. 18. 7
9
1
3
4
9
4
15
2
3
1
4
15
9
10
4
5
1
10
12. 6
8
1
2
5
9
7
18
1
6
16. 2
6
5
18
1
18
20. 8. 1
4
1
2
3
14
2
7
3
8
2
4
7
8
Mixed Review
2 mile on Monday.
21. Jade swam 1
3
lawn. Then he spent 10 hour
mowing his neighbor’s lawn.
How much longer did it take
Monty to mow his lawn than his
neighbor’s lawn?
3
hr
5
© Harcourt
On Wednesday she swam 8 mile.
How many miles did Jade swim
in all?
5 hour mowing his
22. Monty spent 4
2
7
mi
8
2.85
9
.9
23. 143
24.
367,112
60
22,026,720
25.
1 3
4 4
1
26.
36.725
14.294
22.431
Practice
PW87
LESSON 16.5
Name
Use the Least Common Denominator
Find the LCD. Then add or subtract.
1
2
2
8
LCD 8; 3
4
1. 2 1
5 3
LCD 15; 1
1
15
2. 6
8
1
4
LCD 8; 1
3. 2
9
12 4
LCD 12; 1
4
4. Find the sum or difference. Write it in simplest form.
2
8
1
4
8
16
5. 3
8
1
4
9. 2
10
3
5
4
5
7. 6
12
2
6
1
6
11. 4
5
1
10
9
10
15. 1
3
2
9
1
9
19. 6. 10. 1
8
5
8
5
16
1
5
16
2
20
4
5
9
10
13. 17. 14. 18. 7
9
1
3
4
9
4
15
2
3
1
4
15
9
10
4
5
1
10
12. 6
8
1
2
5
9
7
18
1
6
16. 2
6
5
18
1
18
20. 8. 1
4
1
2
3
14
2
7
3
8
2
4
7
8
Mixed Review
2 mile on Monday.
21. Jade swam 1
3
lawn. Then he spent 10 hour
mowing his neighbor’s lawn.
How much longer did it take
Monty to mow his lawn than his
neighbor’s lawn?
3
hr
5
© Harcourt
On Wednesday she swam 8 mile.
How many miles did Jade swim
in all?
5 hour mowing his
22. Monty spent 4
2
7
mi
8
2.85
9
.9
23. 143
24.
367,112
60
22,026,720
25.
1 3
4 4
1
26.
36.725
14.294
22.431
Practice
PW87