Algebra 1 Section 2.1

1
Algebra 1Section 2.1 The Real Number Line
Absolute Value - The distance a number is from 0

7 units
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1
2 3 4 5 6 7 8 9 10
7
For example, the absolute value of 7 7
7 units
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1
2 3 4 5 6 7 8 9 10
The absolute value of 7 -7
7
2
Evaluate the expression.

• - 3
• 3

• - ¾
• ¾

• 6
• 6

• 0
• 0

• - 3.2
• 3.2

3
Graph the numbers on a number line. Which is
greater?
1. 4 and -1
4
-1
4 is greater
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1
2 3 4 5 6 7 8 9 10
2. 4.5 and 5.5
4.5
-5.5
4.5 is greater
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1
2 3 4 5 6 7 8 9 10
3. -2 and 2/3
-2
-2/3
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1
2 3 4 5 6 7 8 9 10
-2/3 is greater
4
Place the following wrench sizes in order from
smallest to largest.
1/2
3/8
7/8
5/8
1
11/16
1¼
3/4
15/16
9/16
1½
1¼
12/16
6/16
14/16
1
11/16
1½
8/16
10/16
15/16
9/16
Change all (under 1) to have a common denominator
3/8
1/2
9/16
5/8
11/16
3/4
7/8
15/16
1
1¼
1½
5
Put the following yardage stats in order
from smallest to largest. (- 4) ( 6) (-
10) ( 25) (- 3) (0) ( 1) (- 1)
( 14) (- 13)
-13 -10 -4 -3 -1 0 1 6 14 25
6
The speed of an object is the absolute value of
its velocity. Velocity indicates both speed and
direction.
For example, a parachutist falling at a rate of
20 feet per second would have
Velocity - 20 feet per second Speed -20
20 feet per second
7
A helicopter is 280 feet above its landing spot.
Twenty seconds later, it lands. What was its
velocity? What was its speed?
Velocity (-280 ft) (20 seconds)
-14 feet per second Speed -14
14 feet per second