Math Lesson 65 Dividing Fractions
Find 12 ÷ 8/9
12/1 x 9/8 = 3/1 x 9/2 = 27/2 = 13 1/2
Find 5/10 ÷ 5/6
5/10 ÷ 5/6 5/10 x 6/5 1/5 x 3/1 = 3/5
Suppose you plan to put the same amount of seed in three feeders. You have 7/8 pound of seed. How much seed will each feeder get?
7/8 ÷ 3 = 7/8 x 1/3 = 7/24
Find 9/16 ÷ 3/4
9/16 ÷ 3/4 9/16 x 4/3 3/4 x 1/1 = 3/4
d. 1 1/2
Deanna's cake recipe needs to be doubled for a party. how much milk will she need for the party cake? a. 3/4 cup b. 2 cups c. 2 1/4 cups d. 1 1/2 cups
reciprocal
One of two numbers whose product is 1; it is also called multiplicative inverse * reciprocal of 6/7 is 7/6
Explain in your own words, what are reciprocals and when are they used.
Reciprocals are a regular fraction such as 4/9 and you flip it so it is 9/4. This is used for dic=vision with fractions.
Dividing Fractions by Fractions
To divide fractions by fractions simply multiply the first fraction by the inverse of the second fraction. 6/7 ÷ 3/7 = 6/7 x 7/3
Dividing Whole Numbers by Fractions
Two numbers are reciprocals if their product is 1. The numerators and denominators are switched in fractions that are reciprocals. To divide by a fraction, multiply by the reciprocal of the fraction. You can remember this by thinking "invert and multiply.
Sam has 3/4 ton of stones to divide evenly among 4 sidewalks. how much stone will be used in each sidewalk? a. 3/16 ton b. 1/3 ton c. 4/3 ton d. 1/4 ton
a. 3/16 ton
1/9 x 5/8 a. 5/72 b. 72/5 c. 45/8 d. 8/45
a. 5/72
Write the reciprocal. a. 7/8 b. 9 c. 3/4 d. 8/7
a. 7/8 8/7 b. 9 1/9 c. 3/4 4/3 d. 8/7 7/8
5/28 ÷ 1/7 a. 1 1/4 b. 4/5 c. 5/196 d. 4/21
a/ 1 1/4
Evaluate x ÷ 20 for x = 2/3. a. 30 b. 1/30 c. 3/40 d. 13 1/3
b. 1/30
3/5 ÷ ? = 3/10 a. 2/5 b. 2 c. 6/13 d. 13
b. 2
Nicole's friend runs 4/9 of a mile, but her distance is only 4/5 of Nicole's distance. how far does Nicole run? a. 9/5 mi b. 5/9 mi c. 45/16 mi d. 16/45 mi
b. 5/9 mi
How many 3/4 cup servings are there in a 6-cup package of rice? a. 12 servings b. 8 servings c. 6 3/4 servings d. 4 1/2 servings
b. 8 serving
Maureen, Frank, Tashia, Zane, Eric, and Wesley are addressing envelopes for volunteer work at a local charity. They were given 3/4 of an entire mailing address to be evenly divided among them. what fraction of the mailing does each person address? a. 1/6 b. 1/12 c. 1/8 d. 1/16
c. 1/8
A cake recipe calls for 5/8 cup of butter. one tablespoon equals 1/16 cup. How many tablespoons of butter are needed to make the cake? a. 16 tablespoons b. 12 tablespoons c. 10 tablespoons d. 8 tablespoons
c. 10 tablespoons
Find the reciprocal of 5/12. a. 7/12 b. 5 c. 21/5 d. 12
c. 12/5
3/4 ÷ 4/5 a. 5/3 b. 1 1/15 c. 15/16 d. 3/5
c. 15/16
Dividing a number by 1/2 will have the same effect as multiplying it by: a. 1/2 b. 1 c. 2 d. 0.5
c. 2
Estimate the product. 3 7/8 • 5 1/9 a. 15 b. 8 c. 20 d. 24
c. 20
Evaluate x ÷ 70 for x = 7/8. a. 61 1/4 b. 80 c. 4/245 d. 1/80
d. 1/80
What is 2 ÷ 1/8 a. 1/16 b. 1/4 c. 4 d. 16
d. 16
Find the reciprocal of 4/19. a. 19 b. 4 c. 15/19 d. 91/4
d. 19/4
What is 7/4 ÷ 3/4 a. 1 5/16 b. 2 c. 2 1/4 d. 2 1/3
d. 2 1/3
6 ÷ 1/5 a. 1 1/5 b. 1/5 c. 5/36 d. 30
d. 30
Divide. 2 1/2 ÷ 1/2 a. 3/4 b. 2 c. 4 1/2 d. 5
d. 5
2/3 ÷ 3/4 a. 1 1/8 b. 1/2 c. 2 d. 8/9
d. 8/9
36 ÷ 4/9 a. 1/81 b. 1/16 c. 16 d. 81
d. 81
