Multiplying Fractions Contexts
What is 1/2 of 5?
1/2 x 5
1/2 of a group of 6 chicken wings
1/2 x 6
Kirsten gave her sister 1/4 of a 500 mL bottle of medicine.
1/4 x 500
combine 2/5 ounces and 3/4 ounces
2/5 + 3/4
Zach has 2/5 of his 10 dollars remaining
2/5 x 10
6 2/3
20/3
5 1/5
26/5
You can use a fraction to express a division problem as something "per" something else.
3 sticks of butter divided among 4 recipes is 3/4 of a stick per recipe
Robert drank 3/4 of a 12 oz. Mountain Dew
3/4 x 12
Lexy has 3/4 of her 4 cookies left
3/4 x 4
What is 4 servings of 1/4 each?
4 x 1/4
4 chests of treasure shared among 7 pirates
4/7 of a chest per pirate
3/4 deducted from 5
5 - 3/4
What is 5 groups of 1/2
5 x 1/2
Briana wants to know the difference between a 6-minute song and 3 1/2 minute song
6 - 3 1/2
You have six rocks, each weighing 1/2 pound.
6 x 1/2
3 1/2
7/2
Bobby has 1/6 gallons more Eric, who has 7/8 gallons. How much does Bobby have?
7/8 + 1/6
20 1/4
81/4
True or False? Does the fraction equal one?
A fraction is equal to one if the numerator and the denominator are exactly the same: 3/3 = 1
5/5 = 1
True 5/5 = 1
Use a whiteboard to write the multiplication sentence that goes with the problem. Remember "times" means "of" or "groups of."
What is 1/2 of 4? 4 x 1/2
3 packs of skittles shared with 5 friends
3/5 of a pack per friend
3 gallons of milk produced by 8 cows
3/8 of a gallon per cow
Multiplication by a fraction also can make groups of fractions. Key words are: times, groups of, each, per, etc.
4 groups of 1/3 is 4 x 1/3 4 boxes of 1/3 ounces each is 4 x 1/3
5 parachutes shared by 12 skydivers
5/12 of a parachute per skydiver
driving 5 hours in 2 days
5/2 or 2 ½ hours per day
8 bags of pancake mix that are 3/4 pound each
8 x 3/4
Multiplying a number by a fraction, is part multiplication (the top) and part division (the bottom).
When the numerator is one, then multiplying by a fraction is just division (the bottom).
What is 1/3 of 6?
1/3 x 6
What is 1/4 of 20?
1/4 x 20
Briana read 3/4 of her 120-page book.
3/4 x 120
Henry drives for 10 days, each day driving 3/5 of a mile.
10 x 3/5
Eric practices 12 times, each time for 1/3 of an hour .
12 x 1/3
How much is 12 groups of 3/4?
12 x 3/4
12 pounds of steak given to 4 hungry lions
12/4 or 3 pounds of steak per lion
4 1/3
13/3
Henry wants to know 4/5 miles less than 2 miles
2 - 4/5
the difference of 1 2/3 and 1/3
1 2/3 - 1/3
the sum of 1 3/4 and 1 3/4
1 3/4 + 1 3/4
Two books read over 3 nights
2/3 of a book per night
LaDainian got 2/3 of Bobby's high score of 600.
2/3 x 600
20/10
False 20/10 = 2
Change the mixed number to an improper fraction
Remember to multiply the whole number by the denominator and add it to the numerator.
True or False? 4/4 = 1
True 4/4 = 1
3/4 of 16 ounces
3/4 of 16
3/2 = 1
False 3/2 = 1 1/2
Write the addition, subtraction, or multiplication expression with fractions
How much is 2 1/2 miles and 2 1/4 miles combined? 2 1/2 + 2 1/4