Adding Integers
5 + (-4)
1
(-3)-6
-9
Joe was swimming 40 ft below sea level. He swam up 22 ft closer to the surface of the water. What is his elevation now?
18 ft below sea level or -18 ft
Define absolute value.
It is the distance (how far) a number is from zero.
What is an integer?
A positive or negative number, or 0, that does not include a fraction or decimal.
(-4)+(-2)
-6
(-6)-2
-8
Sara went up 6 flights of stairs, then down 2 flights, then up 1 flight, and down 3 flights. Where is she now?
Up 2 flights or +2 flights
Positive or Negative: What is the absolute value of a positive number?
Positive
What is the difference between the OPPOSITE of a number and the ABSOLUTE VALUE of a number?
The opposite of a number is the number that is equidistant from zero on a number line. It can be positive or negative. The absolute value is the distance a number is from zero. It is always positive.
(-4)+0
-4
(-4)-7
-11
The temperature in Ottawa, Canada is -12°F. It is 37° colder in Newfoundland than it is in Ottawa. What is the temperature in Newfoundland?
-49°F
Positive or Negative: What is the absolute value of a negative number?
Positive
Review question! What is the formula for finding the circumference of a circle?
C=πd
(-7)+(-7)
-14
6-(-2)
8
The temperature in the morning was -7°F. It warmed up 15° by midday but then cooled off another 34° by midnight. What temperature was it at midnight?
-26°F
What is |-5| + |-8|?
13
Why is it wrong to say that integers are whole numbers?
Whole numbers can’t be negative and integers can!
(-7)+(-2)
-9
(-7)-(-8)
1
The temperature on Mt. Chilly is -7°F. The temperature on Mt. Freezie is 4° more than twice the temperature on Mt. Chilly. What is the temperature on Mt. Freezie?
-10°F
What is |-12| + -|3|?
9
Challenge: Explain the difference between (-3)2 and -32.
The first one (in parentheses) means negative 3 squared, which is -3 * -3. It equals 9.
The second one means -1 * 3 squared. It equals -9.