Today’s Objective
Understand the concept of a ratio and use
ratio language to describe a ratio
relationship between two quantities.
DO NOW: Current understanding
What is a ratio?
Why do we use ratios?
What are some examples of real-world
ratios?
What do those ratios mean?
VOCABULARY
 RATIO: expresses
the relationship
between two quantities. Ratios
compare two measures of the
same types of things
Common Ratios
Days per week
miles per hour
pay in dollars per hour
weeks vacation per year
hours per day
days per year
heart beats per minute
feet per yard
inches per foot
Who Uses Ratios…
Principals use ratios to make sure there are
enough teachers for students in the
building.
The lottery uses ratios to show how many
winners there are compared to tickets
bought
Ratios in our classroom

What is the ratio of boys to girls in our
class?

What is the ratio of girls to boys in our
class?

What is the ratio of teacher to students
in our class?
Your turn:
Come up with 3 more ratios you see from
our class and explain what they mean
Ratio Relationships
Part to Part: student to student
Part to Whole: student to class
Whole to part: class to student
Ratio Relationships
A basket of fruit
contains 6 apples, 4
bananas, and 3
oranges. What is
their relationship
1)
Bananas to Apples
2)
Bananas and Apples to
Oranges
3)
Oranges to Total
Pieces of Fruit
In closing
Research shows that
1 out of 10 people are left-handed. Explain in
words what this means and what does this tell
us about the people who are right-handed.