P1249325492UGwqB

1
Addition of Real Numbers on the number line

• Add real numbers using a number line or addition
  rules
• Solve real life problem such as finding profit

2
Addition Using a Number Line

• Positive numbers go right
• Negative numbers go left

Example
-8 7
-1
right 7
3
Few More Examples
7 (-3)
4
Left 3
8 (-6) (-5)
-3
4
Try this one
-2(-3) 6
5
Rules for Adding Positive and Negative Numbers.
6
How Do I Add Two Positive Numbers?
Examples 1.) 5 2.3 ? 2.) 7 3 ?
7
Adding Two Negative Numbers.
Examples 1.) -1 -2 ? 2.) -2.3 -6 ?
8
A hot air balloon travel up 30 ft. A diver then
dives out of the balloon 50 feet. How far under
the water is the diver when he is finished his
dive?

0 feet
-
9
Rule for Adding Positive and Negatives
Examples 5 (-10) -5 10
Subtract the numbers and take the sign of the
number with the greatest absolute value
10
Using Positive and negative numbers in real life
A company made a table showing the money they
made or lost over 4 months. Did they make a
profit in those 4 months?
March 7,982
April -1,820
May -9,219
June 12,043
11
Properties of Addition
Commutative Property ab ba (order does not
matter) Associative Property (ab)c a (bc)
(the way you group does not matter) Identity
Property a 0 a (zero plus a number is that
number) Property of zero (inverse property) a
-a 0 The sum of a number and it opposite is 0.