Additive Inverse & Absolute Value
What is the additive inverse of -4?
4
solve.
-20 + (-14) =
-34
(-4) - 7
-11
Add and keep the sign
Whole numbers and their opposites.
Integers
What is the additive inverse of 2?
-2
solve.
6.25 + (-8.50) =
-2.25
-24 - (-9)
-15
When adding rational numbers, if the signs are different you should...
subtract and take the sign of the larger value
Numbers that can be written as a fraction.
Rational Numbers
Write a real-world example so that it combines to make zero in the situation:
The temperature during a blizzard is -12 degrees. Then..
The sun came up and the temperature rose 12 degrees. (or similar)
solve.
-54.26 + (-15.42) =
-69.68
solve.
10.8 - (-6.4)=
17.2
When subtracting rational numbers, the first thing you should do is..
Rewrite to add the opposite (Keep, Change, Opposite)
The distance a number is away from zero on a number line.
Absolute Value
Write a real-world example so that it combines to make zero in the situation:
The water level rises to 7 feet above normal. Then...
A summer drought causes the water level to drop 7 feet. (or similar)
solve.
-1 1/2 + 2 7/10
1 1/5
solve.
5/8 - 1 7/8
-1 1/4
Once you have rewritten a subtraction to add the opposite, you should...
Follow the same rules as adding.
a number that is the same distance away from zero, but always on the other side of the number line.
Opposite
Create an equivalent expression using the additive inverse property:
-17 - 25
-17 + (-25)
Precipitation for the month of March was 6 1/2 inches less than average. In April, the precipitation was 2 3/8 inches less than average. How many inches below average was the precipitation for both March and April?
-8 7/8
Mickey borrowed $75.00 from his grandparents to purchase a season pass to a theme park. After saving up his allowance for one month, he is able to pacy them $24.65. How much does Mickey still owe his grandparents?
$50.35
When modeling addition and subtraction on a number line, positive and negative values tell you which direction to go. Which direction do you move for positive values? Negative values?
Positive, Right
Negative, Left
When a number and its opposite are added, the sum is zero.
Additive Inverse