Transcript Ratios

Using Multiplication &
Division to Solve
Problems Involving
Rates
TEKS 6.2C
Lesson 7 (2nd 6 Weeks)
Ratios
• A ratio is a comparison of two
quantities.
• When a ratio is written as a fraction, the
first number is the numerator of the
fraction and the second number is the
denominator. EX: the ratio 1:5 = 1
5
• When a ratio is written with the two
numbers separated by a colon, the
colon is read as the word to and the
ratio 1:5 is read one to five.
Rate
• A rate is also a ratio.
EX: If you walk 7 miles in 2 hours, the
ratio 7:2 refers to the rate at which
you walk.
Use Multiplication & Division to
Solve Problems Involving Ratios
and Rates
• Use multiplication when you want to
combine groups of equal size.
• Division is the opposite of multiplication.
Use division when you want to separate
a whole into groups of equal size.
EX: Using Multiplication
Tommy decided that he wanted to buy a
new TV set at Wal-mart. He will make
payments of $96 a month for a year.
How much will Tommy pay for the TV at
the end of the year?
Tommy decided that he wanted to buy a new TV set at Wal-mart. He will make
payments of $96 a month for a year. How much will Tommy pay for the TV at the
end of the year?
• We know that there is 12 months in a
year. Since Tommy will be paying $96 a
month. We need to multiply $96 by 12
to figure out the total amount of the TV.
Tommy decided that he wanted to buy a new TV set at Wal-mart. He will make
payments of $96 a month for a year. How much will Tommy pay for the TV at the
end of the year?
1
96
x 12
19 2
+ 960
11 5 2
1
Tommy will pay
$1152 for the TV in
a year.
EX: Using Division
• A short order cook makes omelets at a
breakfast diner. Each omelet takes 3
eggs. The cook has 36 eggs. How many
omelets can he make?
12
3 36
-3
06
-6
0
The cook can
make 12
omelets.