Multiply Whole Numbers by Fractions
5 × 1/3 = ______
5x1/3 = 5/3
You walk 2 1/10 miles. Your friend walks 1/3 of the distance you walked. Does your friend walk fewer miles, more miles, or the same number of miles as you?
2 1/10 > 1
1/3 < 1
When you multiply 2 1/10 by a fraction less than 1 your number decreases.
less miles
DAILY DOUBLE
4/8 x 1/4 =
4 x 1 / 8 x 4
4/32 simplify divide by 4 = 1/8
___ x 7/8 = 21/8
3 x 7 = 21
3
A professional athlete spends 1/4 of
each day at practice. How many
hours does she spend at practice
in 1 week?
1/4 = 1 day
7 days = 1 week
1/4 x 7 = 1x7/4 = 7/4 hours in a week
Find the area of a square with a
side length of 3/10
square all sides are the same
3/10 x 3/10 = 3 x 3/ 10 x 10 = 9/20 square units
DAILY DOUBLE
You have band practice 3 times this week. Each practice lasts for 2/5 hour. How much time do you spend in band practice?
2/5 x 3 = 2x3/ 5
6/5 or 1 1/5 hour
There are 30 students in your
class. Three-tenths of the students
walk to school, two-fifths of the
students ride the bus to school,
and the rest get a ride from a
parent. How many students get a
ride from a parent?
3/10 of 30 = 3 x 30 / 10 = 90/10 simplify divide by 10= 9/1 = 9 students
2/5 of 30 = 2 x 30 / 5 = 60/5 simplify divide by 5= 12/1 =12 students
12 + 9 = 21
30 - 21 = 9 students get a ride from a parent
Find the area of a rectangle with side lengths of 7/12 and 4/5.
7/12 x 4/5
7x4 / 12 x 5
28/60 = simplify divide by 4 = 7/15 units squared
You run 9/4 miles each day for 3 days. Your goal is to run at least 8 miles.
Do you meet your goal?
9/4 x 3 = 9 x 3/4
27/4 =
4 goes into 27 6 times which equals 24 and we have 3 left over
6 3/4 miles. No you did not meet your goal because 6 3/4 is less than 8 miles.
DAILY DOUBLE
Apples cost 1 1/2 dollars for each
pound. Your friend has $5. Does
she have enough money to buy
2 2/5 pounds of apples?
1 1/2 = 3/2
2 2/5= 12/5
3/2 x 12/5 = 3 x 12/ 2 x 5=36/10
simplify by 2 = 18/5 =
5 goes into 18 3 times which is 15 and you have 3 left over = $ 3 3/5, therefore she has enough money to buy the apples
A granola recipe calls for 1/4 cup of dried fruit. You only want to use 1/3 of that amount. What fraction of a cup do you want to use?
1/4 x 1/3 =
1 x 1 / 4 x 3=
1/12 of a cup
You swim 13/3 laps each day for 2 days. Your friend swims 9/4 laps each day for 3 days. Who swims the farther distance? How much farther?
You swim 13/3 x 2 = 26/3
Your friend swims 9/4 x 3 = 27/4
You swim 26/3 = 8 2/3
Your friend swims 27/4 = 6 3/4
You swim more.
8 2/3 - 6 3/4 = 8 8/12 - 6 9/12 = 7 20/12 - 6 9/12
1 11/12 more laps
A chef makes 4 3/4 quarts of tomato
soup to serve for lunch. He makes
1 2/5 times as many quarts of tomato
soup to serve for dinner as he
does for lunch. How many quarts
of soup does the chef make in all?
19/4 x 7/5 = 133/20 quarts
6 13/20 + 4 3/4
6 13/20 + 4 15/20 = 10 28/20 or 11 8/10 = 11 2/5 quarts
You run a lap in 1/10 hour. You want to run the lap in half of that time. In what fraction of an hour do you want to run the lap?
1/10 x 1/2 = 1/20 hour