Sections 2.1, 2.2

Positive and Negative Numbers

(Part 1)

What are integers?

The whole numbers and their opposites.

…-3, -2, -1, 0, 1, 2, 3…

(Numbers marked on a standard number line.)

Graph the following integers.

-5, -1, 10, 4, -9

Graph the following integers.

-5, -1, 10, 4, -9

What do the following symbols mean?

<, >, =

What Is Absolute Value?

The distance a number is from zero.

Evaluate each expression.

Example 1-4dEvaluate each expression.

5z 10xy

Let x = 3, y = 12, z = -9

4 -  you could teach it right now3 – you could ace it on a test2 – you could give an example1 – may of heard of it, but that’s about it

Rules for Adding Integers

Same Signs:

Add the two numbers and use the same sign.

Different Signs:

Subtract the two numbers, use the sign of the number with the larger absolute value.

Evaluate the following expressions.

Same Signs:

Add the two numbers and use the same sign.

Different Signs:

Subtract the two numbers, use the sign of the number with the larger absolute value.

38 + (-23) =

-14 + (-15) =

-35 + (-39) =

-34 + 21 =

Evaluate the following expressions.

Same Signs:

Add the two numbers and use the same sign.

Different Signs:

Subtract the two numbers, use the sign of the number with the larger absolute value.

Homework

Practice 2.1, 2.2 All