Drill #17*Name the set of numbers graphed. Name the set

of numbers that each number belongs to:

1.

2.

3.

-2 -1 0 1 2-3

-2 0 2

-1 0 1

2-1 Integers and the Number Line

Objective: To state the coordinate of a point on a number line, to graph integers on a number line, and to add integers by using a number line.

HW 2-1 pg 75, #16-40 (even)

Copy problems, show work.

Heading Title, & Objective!

Write an addition sentence

Start at -1, add 3, subtract 5 (add negative 5)

-1 + 3 – 5 or -1 + 3 + -5

-2 -1 0 1 2-3

+3-5

Venn Diagram for Real Numbers

Reals, R

I = irrationals

Q = rationals

Z = integers

W = wholes

N = naturals

I QZ

WN

Graph and Coordinate ** (6., 7.)

6. Graph: To plot a point on number line.

7. Coordinate: The number that corresponds to a point on a number line.

Name the coordinate of the point that is graphed on the number line below.

-2 -1 0 1 2-3

Graph each set on number line* (# 17)

4. { -1, 0, 1, 2 }

5. Integers less than zero

6. Integers less than zero but greater than -6

Rewind…

A number line is …

Natural Numbers are ?Whole Numbers are ?Integers are ?

All Natural Numbers are in the set of _______ and _______

All sets of numbers are contained within the set of ____________ numbers.

2 – 3 Adding and Subtracting Integers

Objective: To find the absolute value of a number, and to add and subtract integers.

Absolute Value ** (8.)8. Absolute Value: The absolute value of a

number is its distance from zero on a number line.

An absolute value is a distance. Distance is always positive.

Examples: -15 = 15

15 = 15

Evaluating Absolute Values

To evaluate an absolute value you must first simplify the expression inside the absolute value.

**Do not evaluate the absolute value until everything inside the absolute value has been simplified.

Classwork (#17)*

Evaluate the following expressions if x = -10

7. x

8. -x

9. - x + 6

10. x – 6

Adding Integers **(9.)

9. Adding Integers:

To add integers with the same sign, add their absolute values. The result keeps the original sign.

To add integers with different signs, subtract the smaller absolute value from the bigger absolute value. The result gets the same sign as the integer with the bigger absolute value.

Find each sum

-10 + (-17)

39 + (-22)

-28 + 16

Additive Inverse Property **(10.)

10. Additive Inverse Property:

For every number a, a + (-a) = 0

An additive inverse of a number, is its negative value. What is the multiplicative inverse of a number?

Subtracting Integers **(11.)

11. Subtracting Integers:

To subtract a number, add its additive inverse.

For any numbers a and b,

a – b = a + (-b)