Inequalities
SWBAT WRITE INEQUALITIES AND IDENTIFY SOLUTIONS USING
REAL-LIFE EXAMPLES.
Do Now (10 minutes)
1. A coach bought t-shirts for a team and spent a total of $168. If each shirt cost $6, how many t-shirts did the coach
buy?
A 21
B 24
C 28
C 34
2. Ms. Bryant puts pens and pencils in gift bags for her students.
She has 72 pencils and 54 pens. Each bag will have the same number of pens and pencils.
No pens or pencils will be left over.
What is the greatest number of gift bags Ms. Bryant can make?
A) 6
B) 8
C) 9
D) 18
3. Stacy worked 6 hours each day for 6 days. She earned a total of $234. How much did Stacy earn per hour?
A) $6.50
B) $13.00
C) $19.50
D) $39.00
4. A car traveled 360 miles in 9 hours. What is the average rate of the car in miles per hour?
A) 40
B) 60
C) 80
D) 360
Vocabulary
An inequality shows a relationship between quantities that are not equal. There is more than
one solution.
Symbols you will see:
Symbol
Meaning
>
Greater than
<
Less than
<
Less than or equal to
>
Greater than or equal to
How it will look graphed on a number line
Tricks for remembering
Remember, the less than symbol < looks like a
sideways L for Less.
Which ever side is open is like a shark eating the
bigger part.
Thinking about inequalities in the real
world
“Children under 12 eat free.”
Who does this apply to? What ages eat free?
All these numbers are LESS THAN 12.
What symbol shows this?
<
If a stands for ages, then a < 12
Thinking about inequalities in the real
world
“The speed limit is 65 miles per hour”
What speeds can you go without getting a ticket?
Is 65 included?
Yes!
These numbers are LESS THAN OR EQUAL TO 65.
What does the symbol look like?
If s represents speed limit, s < 65
<
Brainstorming…
Take 5 minutes with a partner and come up with a list of words that
could mean greater than, less than, greater than or equal to, or less
than or equal to.
Words we can use
Inequality words
Under
Less than
Decrease
Less than <
Over
More than
increase
°
Less than or equal to < •
at most
Limit
Maximum
And younger
Or less
Greater than >
°
Greater than or equal to > •
At least
Minimum
And older
Or more
Practice

The ride is only for children under 3 feet tall. What are the
possible solutions? Write the inequality.

Seniors over the age of 65 receive a 10% discount. What
are the possible solutions? Write the inequality.

The gym holds a maximum of 1000 people. What are the
possible solutions? Write the inequality.

Must be at least 16 years old to drive a car. What are the
possible solutions? Write the inequality.
Homework
Write this down on a separate sheet of paper and complete as homework.
1. Name each of the following symbols:
<
>
<
>
2. Name 5 possible solutions to x > 9
3. Name 5 possible solutions to x < -1