Real-World Examples
The concession stand made a profit of $135 on Saturday and lost $12 on Sunday. How much profit did the concession stand make over the weekend?
$123
Add the following:
1/2 + 1/4
3/4
Subtract the following:
1/4 - (-1/4)
1/2
When adding decimals what do we need to line up?
The decimal points.
The tenths places line up, the hundredths places line up, the thousandths places line up...
Negative plus negative =
NEGATIVE
Gary bought 2.756 lbs of nails for his project. If Gary uses 1.38 lbs of nails, how many nails does Gary have left?
1.376 lbs
Add the following:
-1+0.52
-0.48
Subtract the following:
-11/6-(-4/3)
-1/2
TRUE OR FALSE: The rules for adding integers are the same as those for adding rational numbers.
TRUE
What do you do if you are adding a negative and a positive?
Subtract and the number farther away from zero gets the sign.
A diver is 13/6 miles below the surface of the water. A second diver is below the other diver by 5/3 miles. How far from the surface of the water is the second diver?
(Hint: Think about direction)
-23/6 miles from the surface of the water.
Add the following:
-1/7+2/3
11/21
Subtract the following:
-4.8-(-5.008)
0.208
What is the first step for adding rational numbers?
Find the LCM of the denominators
What do you do when you subtract a negative?
You add the integers.
You are going on a trip and need to buy camping gear. You have $20.00 to spend. If the tent is $9.53, the lantern is $3.23, and the sleeping bag is $6.58. Do you have enough money to buy everything?
Yes
Bonus Points: How much money will be left over?
Add the following:
-6.84+0.9
-5.94
Subtract the following:
3/4-1 1/5
-9/20
How do we change subtraction of integers to addition of integers?
Add-the-opposite
What is always true about absolute value?
Always positive
The water level in the Colorado River is 2.55 meters below average. A large rainfall cause the water level to rise 0.8 meters. What is the water level after the rainfall?
-1.75 meters
Add the following:
-2 3/4+5/3
-13/12 = -1 1/12
Subtract the following:
-6-4.37
-10.37
What is the second step of adding/subtracting rational numbers?
Add/subtract the numerators.
What is the additive inverse of -9?
9
Bonus Points: Why is it the additive inverse?