Equivalent Fractions and Common Denominators
3/8 and 7/10 find equivalent fractions with a common denominator
30/80 and 56/80
20/100 in simplest form
1/5
1/4 + 4/5
21/20
3 1/2 + 1/6 + 4 5/6
8 1/2
Understand the problem. What do you know? What do you need to find? Explain.
You have a pitcher of water. You pour 1 2/3 cups on a plant. You pour 2 1/8 cups in your dog’s dish, and your pour 1 5/8 cups in a vase. You have used all of the water. How much was in the pitcher to begin with?
You know:You pour 1 2/3 cups, 2 1/8 cups, and 1 5/8 cups of water from the pitcher. You use all the water.
You need to find: How much water there was
Newton pours 2/3 cup of milk on his cereal and 3/4 cup in a glass. Use a common denominator to write an equivalent fraction for each fraction.
8/12 and 9/12
Newton went to school 12 out of 30 days in April. What fraction of the days, in simplest form, did he not go to school?
18/30 = 3/5
Of the pets in the pet store, 1/10 are birds, 1/2 are mammals, and 1/8 are reptiles. The rest are fish. What fraction of the pets are birds, mammals, or reptiles?
29/40
DAILY DOUBLE
A chef serves 8 3/4 gallons of soup for lunch and 10 2/3 gallons of soup for dinner. How much soup did he serve in all?
19 5/12 gallons
Understand the problem. Then make a plan. How will you solve? Explain.
Of the books checked out of the library last week, 2/7 were mysteries and 15/28 were poetry. The rest were nonfiction. What fraction of the books were nonfiction?
Add the two known fractions. Subtract the sum from 1. The result is the fraction of books that were nonfiction.
You have a tomato plant that is 4/9 yard tall and a bean plant that is 5/12 yard tall. Are the plants the same height? Explain.
No 16/36 is not equal to 15/36
DAILY DOUBLE
5/8 + 4/10
1/2 + 1/2 = 1
There are 50 states in the United States. Of those,7/25 border the Atlantic Ocean and 1/10 border the Pacific Ocean. What fraction of the states border the Atlantic or Pacific Ocean?
19/50
6 - 3 1/3
2 2/3
Understand the problem and make a plan. How will you solve?
A man has 7 5/8 gallons of gasoline in his car. He uses 3 1/2 gallons to get to work and 1 1/4 gallons to get to his son’s school play. How many gallons of gasoline does he have left?
Subtract the sum of 3 1/2 and 1 1/4 from 7 5/8 to find how many gallons he has left.
Which pair of fractions is not equivalent to 1/3 and 5/9?
6/18 and 10/18
12/36 and 20/36
30/90 and 50/90
9/27 and 18/27
9/27 and 18/27
You drink 6 3/8 cups of water during a hike. Your friend drinks 5 7/8 cups of water. About how much water do you and your friend drink in all?
6 1/2 + 6 = about 12 1/2 cups
7/10 - 3/8
13/40
4 3/10 - 1 4/5
2 1/2
Your library book has 90 pages. You read 11/90 of the book on Friday and 23/45 on Saturday. You read the rest of the book on Sunday. How many pages do you read on Sunday?
33 pages
You ride your bike 3/4 mile and skateboard 7/8 mile. Do you travel the same distance on each? Explain.
No, you travel 6/8 mile on your bike
Explain how you know 5/6 - 2/5 is about a half
5/6 is about 1 whole and 5/12 is about a half and 1 - 1/2 = 1/2
You want to run a lap around the playground in 5/6 minute. Your first attempt takes 9/10 minute. Your second attempt takes 1/5 minute less than your first attempt. Did you meet your goal?
yes
You ride your bike to school. It weighs 17 3/4 pounds. Your friend rides his skateboard. It weighs 8 2/5 pounds. How much heavier is your bike than your friend’s skateboard?
9 7/20 pounds
Your family spends 14 hours at a theme park. You spend 1/14 of the hours in the petting zoo and 5/7 of the hours on the rides. You spend the rest of the time watching shows. How many hours does your family spend watching shows?
3 hours