Name: Date: Math 6B Class work: Lessons 5-­‐2 and 5-­‐3 Lesson 5-­‐2: Zero & Opposites., Lesson 5-­‐3: Rules for Adding Positive & Negative Numbers Opposite Numbers: Two integers are opposites if they are each the same
distance away from zero, but on opposite sides of the number line.
-( 2) = -2
-(-2) = 2
“the opposite of 2 is negative 2”
“the opposite of negative 2 is 2”
The sum of 2 opposite numbers is zero: -2 + 2 = 0
Absolute Value:
The absolute value of a number is its distance from zero on the number line.
|-3| = 3
| 3| = 3
“the absolute value of negative 3 is 3”
“the absolute value of 3 is 3”
The absolute values of opposite numbers are equal: |-3| = |3| = 3
The minus symbol - has 3 meanings in math:
1. Subtraction:
2 – 3 : meaning "2 minus 3"
or "2 take away 3"
or "the difference of 2 and 3"
2. Negative:
-2
: a negative number, read as "negative 2"
3. The opposite:
Examples:
-2
: "the opposite of 2"
-|3|
: "the opposite of the absolute value of 3"
-(-2) : "the opposite of negative 2" or “the opposite of the opposite of 2”
We have had some practice adding and subtracting integers.
We can use what we know with negative and positive decimals and fractions.
Use the coordinates to find the lengths of each line:
AB =
CD =
EF =
GH =
IJ =
KL =
Read through lessons 5-2 and 5-3 and find definitions for the following.
Provide an example for each definition.
Addition Property of Zero:
Property of Opposites:
Opposite of Opposites (Op-op) Property:
The Absolute Value of a Number:
Rule for adding 2 negative numbers:
Rule for adding a negative number and a positive number:
Practice what you know!
Complete the following problems from Lessons 5-­‐2 and 5-­‐3 as necessary:
page 246, #17-26, 29-32 and page 251, #13-32