Rules of Addition
Positive + Positive =
Positive
What does KCC stand for?
Keep Change Change
True or False.
We do not use KCC when adding and subtracting fractions and decimals.
False
-1 + 4
A scuba diver starts his dive at 3 feet below the surface. He dove another 6 feet down into the water. What is the elevation of the diver now?
-3 - 6
-3 + -6
-9 feet
Positive + Negative =
Depends on the greater absolute value
When should you use KCC?
On a subtraction problem
When adding and subtracting decimals, the rules are the same except we also _________________ before adding and subtracting.
line up the decimals
Order from least to greatest:
2, 0, l-3l, -8, l5l, -1
-8, -1, 0, 2, l-3l, l5l
In Buffalo, New York, the temperature was 3oF in the morning. If the temperature drops 7oF, what is the new temperature?
3 - 7
3 + -7
7-3
-4oF
When adding two rational numbers with DIFFERENT signs, we _________ the two numbers.
subtract
The purpose of KCC is to rewrite a subtraction problem so that we ______ the __________.
add, opposite
Before we add and subtract the ____________ in the fractions, we first need to get __________ ___________.
numerators, common denominators
-7 + -2
-9
Emily borrowed $3.94 from her brother. She got $15.50 for her birthday. After she pays back her brother, how much money will she have left over?
15.50 - 3.94
15.50 + -3.94
$11.56
When two rational numbers are equal distance from 0 but on different sides of 0, they are called _________.
opposites
Evaluate.
2 - (-5)
7
Evaluate.
3/4 + 3/8
9/8 or 1 1/8
3 - 11
-8
Chen ate 5/8 of a pizza. His cousin ate 1/2 of another pizza. How much pizza did they eat together?
5/8 + 1/2
5/8 + 4/8
9/8 or 1 1/8 pizzas
What is the name of the property that states any rational number plus its opposite will equal 0?
Additive Inverse Property
Evaluate.
-6 - 12
-18
Evaluate.
7/3 - 2/9
19/9 or 2 1/9
-5 + (8) - 6
-3
Steve has overdrawn his checking account by $27. His bank charged him $15 for an overdraft fee. Then he quickly deposited $100. What is his current balance?
-27 - 15 + 100
-27 + -15
-42 + 100
$58