Download 2.1 Integers, Rational Numbers Notes (Key)

Algebra I
2.1 Use Integers and Rational Numbers
NOTES
I. Classroom Example
What number do you have?___________
Plot the number on the number line below:
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
10
After the class example, what can you tell me about this number?_________
II. Now Fill in the chart showing the relationship between Whole, Integers,
Rational and Real numbers:
Algebra I
-9
-8
-7
2.1 Notes
-6
-5
-4
-3
-2
-1
0
1
page 2
2
3
4
5
6
7
10
III. Opposites: -a
Plot the numbers 4 and -4 on the number line above. These are called
OPPOSITES.
Find -a (i.e. the opposite) of the following numbers:
a) 8
b) -3.6
c) ½
IV.
Absolute Value:
d)
 13
a
How far from zero is 4 on the number line above?____________
How far from zero is -4 on the number line above?______________
When asked for a distance from zero, the absolute value symbols are used.
For Example:
Instead of asking “How far from zero is -3?”, you would ask like this:
3 = and the answer would be “3 units”.
An absolute value is always positive because it refers to a distance.
Find a (i.e. the absolute value) of these examples:
a)
9
b)
12
c)
2 3
d) 1  15