# Lesson 2.1

```Bell Ringer #1
• Evaluate
1.
4𝑛 2 𝑓𝑜𝑟 𝑛 = 2 2. 𝑝1 𝑓𝑜𝑟 𝑝 = 24
Multiply
3. 5 𝑎 + 𝑏 + 𝑑
4. 7(3𝑧 + 𝑦 + 2)
2.1 Integers and the Number Line
• Whole numbers: 0, 1, 2, 3, 4, …
• Opposites: Numbers that are the
same distance from zero, but on
the opposite side of zero
–Ex: 3 (“positive three”)
and – 3 (“negative three”)
• Integers: consists of the positive
whole numbers, negative whole
numbers, and zero
{… - 4, -3, -2, -1, 0, 1, 2, 3, 4, …}
• Name the integer that is suggested by each
situation.
• 1. Death valley is 282 ft below sea level
• 2. The temperature is 3&deg; below 0
• 3. The halfback made a gain of 8 yards
• 4. Mikey's juice stand made an \$18 profit on
Monday
You Try
1. The quarterback lost 9 yards.
2. Susie saved \$15 for her allowance.
Inequalities
An inequality is a sentence that
compares two values.
&lt;
Less than
&gt;
Greater than
2 &gt; -4
5&lt;7
“2 is greater than 4”
“5 is less than 7”
Write a true sentence using &gt; or &lt;
2 ____ 9
-18 ____ -15
-7 ____ 3
-15 ____ -5
6 ____ -12
11 ____ -2
Absolute value
• The distance from zero.
• |n| = “the absolute value of n”
• ALWAYS positive!!!
Examples
1. |12|
5. |3|
2. |-7|
6. |-3|
3. |-3.04|
7. |21|
4. |0|
8. |-14|
Ticket Out The Door
Name the integer that is suggested by each
situation.
1. The running back lost 9 yards
2. Mike made a profit of \$200
Use &gt; or &lt; to make a true sentence. Simplify
absolute value first.
3. −11 ____ 9
4. 9 ____ −10
```