Transcript 2 - Lamar Consolidated ISD

1
4
What is this?
Do you have any cousins?
Fractions have “cousins” too.
They are called
RATIOS
Ratios
2
5
2:5
2 to 5
3
8
3:8
3 to 8
15
10
15:10
15 to 10
What is a ratio?



Compares two numbers by division
Part:Whole Whole to Part
Part
Part
Can be simplified, but not written as a
mixed number
Order is important and the terms of a
ratio should be in the order asked to give
them
Ratio Box
Item
Ratio
(# have)
A ratio is a mathematical way to compare
two quantities.
Example…
There are 2 teachers and 26 students in Mrs. Reed’s 2nd
period class.
So, the ratio of teachers to students is…
2 to 26
2 : 26
2
26
Item
Ratio
(# have)
teachers
2
students
26
But, if you were asked to find the ratio of students to
teachers, you would need to put the student number first!!
Item
26 to 2
26 : 2
26
2
Ratio
(# have)
students
26
teachers
2
The ratio of teachers to students is….
2 to 26
Quantities are easier to understand when we use small
numbers. So….
Every time you write a ratio, be
sure to reduce it by dividing if
possible!!!
Let’s practice…
Are these ratios in lowest terms, or can we
reduce them by dividing?
10 : 12
14 : 28
5 : 31
8 : 32
7 : 35
16 : 48
You can also make equivalent ratios by multiplying….
The ratio of pickles to popcorn sold in the Lamar Little League
Concession Stand each night is 4 : 7.
Let’s make a t-chart of some
possible sales numbers for Tuesday
night.
Each hour at McDonald’s, the ratio of ice creams sold to orders placed is 2:9.
Which could be the ratio of ice creams sold to orders placed yesterday from 6 –
7 PM?
A 20 : 72
B 10 : 27
C 14 : 63
Now it’s time for you to practice ratios……
Good luck!!!!!