Adding and Subtracting Fractions
1/6 + 2 1/4 =
2 5/12
1 5/6 + ____ = 2
1 5/6 + 1/6 = 2
1/3 of 60
1/3 of 60 = 20
Which is a better buy?
4 cans for $3 or 8 cans for $6?
Both purchases are the same price per can. Both are $0.75 per can.
Mark drove 3/4 of a 36 km trip before he stopped to get gas for his car. How many kilometers had Mark driven at that point? Show your work using words, numbers, or labeled sketches.
¾ × 36 = 27
5/6 + 1/3 =
21/18 or 1 3/18
____ + 5/8 = 3/4
1/8 + 5/8 = 3/4
1/5 of 100
1/5 of 100 = 20
Which is a better buy?
5 cans for $6 or 8 cans for $10?
5 cans for $6 is a better buy because 5 divided by 6 is 1R1. $1 divided by 5 is $0.20 so each can is $1.20. 8 cans for $10 is $1.25.
Abby is 5 1/2 feet tall. Craig is 5 1/3 feet tall.
a Who is taller?
b How much taller? Show your work.
5/6 - 1/3 =
9/18 or 3/6 or 1/2
3 1/4 - ____ = 1
3 1/4 - 2 1/4 = 1
1/3 of 27
1/3 of 27 = 9
Which is a better buy?
12 bags for $15 or 16 for $19.20
12 bags = $1.25
16 bags = $1.20
12 bags for $15 is the better buy
Shawn made a mix of lettuce seeds to plant. Th e mix has 1/2 cup of green leaf seeds, 2 2/3 cups red leaf seeds, and 1 1/4 cups bronze leaf seeds. How many cups of seeds does Shawn have to plant? Show your work.
Shawn has 45⁄12 cups of seeds to plant.
Example: ½ + 22⁄3 + 1¼ = 6⁄12 + 28⁄12 + 13⁄12 = 45⁄12
Write equivalent fractions with common denominators to solve:
3 4/15 + 2 1/3 =
3 4/15 + 2 1/3 = 3 4/15 + 2 5/15 = 5 9/15
3 2/3 + ____ = 4
3 2/3 + 1/3 = 4
1/12 x 60
1/12 x 60 = 5
Which is a better buy?
20 bars for $23 or 8 bars for $10
20 bars for $23 = $1.25
8 bars for $10 = $1.25
There are the same
Andrea worked out by walking and running on a park trail. She walked 2/5 of the trail and then ran 1/4 of the trail.
a. How much of the trail had she covered? b. Did Andrea walk farther or run farther? c. How much farther?
a. How much of the trail had she covered? Andrea covered 13⁄20 of the trail. 2⁄5 + ¼ = 8⁄20 + 5⁄20 = 13⁄20
b. Did Andrea walk farther or run farther? Andrea walked farther.
c. How much farther? Andrea walked 3⁄20 of the trail farther than she ran. Work will vary. Example: 2⁄5 walked – ¼ ran = 8⁄20 – 5⁄20 = 3⁄20
10/16 - 5/8 =
10/16 - 5/8 = 10/16 - 10/16 = 0
____ + 2/3 = 5/6
1/6 + 2/3 = 5/6
3/4 of 60
3/4 of 60 = 45
What is the better buy?
12 cans for $10 or 9 cans for $9?
12 cans for $10 = $1.20
9 cans for $9 = $1
9 cans for $9 is the better buy.
David ran 1 2 a mile down at the high school track and then walked 1 3 of a mile.
a. How far did David go in all? Use numbers, labeled sketches, or words to solve this problem. b.When Sara solved this problem, she got 2 5 of a mile for her answer. Is this a reasonable answer? Why or why not?
a. How far did David go in all? Use numbers, labeled sketches, or words to solve this problem. David traveled 5⁄6 of a mile in all.
c. When Sara solved this problem, she got 2 5 of a mile for her answer. Is this a reasonable answer? Why or why not? No Sara's answer is not reasonable. David has to have gone more than ½ a mile because just the run alone was that much, but 2⁄5 is less than ½ .