Transcript Integer and Absolute value notes

Integers and
Absolute Value
Section 2-1
Intro toI ntegers
• An integer is the set of whole numbers
and their opposites, including zero,
represented by {… -3, - 2, - 1, 0, 1, 2,
3,…}
• A positive integer is a whole number
greater than zero.
• A negative integer is w whole number
less than zero.
• Website for Integer Rules
T
h ings to remember
• Graph – means to draw a point on
the number line to represent the
integer.
• Zero is neither positive nor negative.
• Absolute value refers to the
distance away from zero an integer
is. (ALWAYS positive!)
How do I know if it is positive or
negative?
• Reference to zero.
• Ask yourself, “Is it good, did it help?”
• Look for key words:
–Negative: below, loss, withdraw, less
than, etc…
–Positive: above, profit, deposit, more
than, etc…
Absolute Value
• Key points for absolute value:
–Always positive because it refers
to distance from zero, not position
on the number line.
–Treat them like ( ). Solve the inside,
then take the absolute value.
–Simply remove the sign, keep the
number!
Practice!
 19
10   14  9 
15  13   8 
Comparing and
Ordering
Integers
Section 2-2
How to read th e signs
• < (less than)
• > (greater than)
• Example 1:
4<8
 4 is less than 8
• Example 2:
– 5 > – 16
 negative 5 is greater than
negative 16
OrderingI ntegers
• WARNING! graph or picture where
the negative numbers fall on a
number line.
• *It may be easier to think, “is this
negative number MORE negative
that one?”
True or False! W
h y?
 19  19
 9   15
15   8  7
Homework
• Worksheet
–Practice 2-2, All
–Skills Practice, Even