Key Terms
The set of numbers less than zero.
negative numbers
The rule for adding two numbers with the same sign.
add the digits and keep the sign
-20 + (-14) =
-34
What is |−3.1|
3.1
The set of numbers that can be written as a fraction. (The denominator cannot be zero.)
rational numbers
The distance between a number and zero.
absolute value
The rule for adding two numbers with different signs.
subtract the digits and take the sign of the number with the larger absolute value
19 + (-7) =
12
What is −|−6|
−6
During the day, the temperature increases by 4.5 degrees. At night it decreases by 7.5 degrees. Find the overall change in temperature.
4.5 + (-7.5) = -3
Two different numbers that have the same absolute value.
opposite numbers or additive inverses
Having a greater absolute value means.
the distance from zero is farther
-15.7 + -9.2 =
-24.9
What is |5.5 + (−6.6)|
1.1
A football team loses 3.5 yards on their first play. Then gains 3.5 yards on their next play. What is the overall increase or decrease in yards?
-3.5 + 3.5 =0
The set of whole numbers and their opposites.
integers
Will the answer be positive or negative? -13 + (-2)
Negative
-1.8 + 3.3 =
1.5
l-1l, 4, -l-2l, 0, 3, -5 from greatest to least
4, 3, 1, 0, -2, -5
-5+(-3)+(-12)+(-23)+2=
-41
Numbers that can be written as a fraction
Rational Numbers
Will the answer be positive or negative? 11 + (-5) =
Positive
(-1 1/5) + 7/15 =
-11/15
Order from least to greatest: 2.1, |−3.5|, −2.5, 4 1/2 , |4.6|
-2.5, 2.1, 3.5, 4 1/2, 4.6
Tina spent $5.25 on craft supplies to make friendship bracelets. She made 3.75 on Monday. On Tuesday she sold an additional $4.50 worth of bracelets. What was Tina's overall profit or loss?
-5.25 + 3.75 + 4.50 = 3
She made a profit of $3