I left the high school and drove right 100 ft., but then turned around and drove left 200 ft. Draw a picture representing the situation.

Write your name on the warm-up and place in the m&m bucket

Warm-up

Chapter 2: Operations with

IntegersLEQ: What are the properties of different kinds

of integers and how do we use them to simplify expressions?

The number line above represents all the real numbers both integers and rational and irrational numbers.

For now we will be looking at only the integers which are all the whole numbers and their opposites.

2.1 Integers and Absolute Value

To graph or plot an integer, place a point on the number line. The number that corresponds to a point is called the coordinate of the point.

Ex. 1: Name the coordinates of M, A, and Z.

Which is bigger, -18 or -12?

10-3 3 4

ZAM P

Try Ex. 2

Cards

How far did you walk left?

The (-) is important so that we know what direction we went, so how can we represent the distance using a negative number???

From your house, you walk right 10 steps and back 20 steps. Can you graph this on the number line?

The absolute value of a number is the positive value of the number aka the distance to that number from the point 0.

*What is the distance from 0 to 10?l l = “absolute value of”l10l=

l-10l=

Absolute Value!!!

l-4l= l-19l= l42l=

l4-3l l-4-2l= l-3l-l7l=

Let’s do some examples as a class

Simplify:

- -15-5

Warm-up

Try 1-6:

Wkst.

7) -5___5 8) l-8l____l8l

9) -18___-12 10) -7___l-7l

Practice

I had $120 for my bill this month, but my bill ended up being $140. How many dollars am I in debt?

Get out your homework!!

Warm-up

You can add integers using a number line.

   Start at the 1st integer. If you add a positive number move to the

right that many units If you add a negative number move to the

left that many units

2.3: Adding and subtracting integers

1) -4 + 3 = _____

2) 6 + -5 = _____ 

3) -2 + - 6 = ______

4) 5 + - 12 = ____

You can also add integers using the sign rules

A) To add 2 integers with the same sign add their absolute values and keep the same sign.

B ) To add 2 integers with different signs find the difference of their absolute values and keep the sign of the greater absolute value.

5) -4 + - 6 = _______

6) 12 + - 8 = ________  7) -10 + 13 = _______

8) - 20 + - 9 = _______   9) 16 + - 8 = _______

10) 13 + -24 = _______

Let’s Practice

Try 11-14 on your own, check your answers with a neighbor

Must use a believable situation Must involve adding integers at least 3 times Must add integers with different signs at least

once.

Ex.: I earned $50 at work. I spent $30 on new headphones for my ipod. When I came home my mom gave me $20 for helping out around the house. However my cell phone bill came a week later and cost me $82. How much money do I have or am I in debt?

Ok, now Create a real-life problem…

Maria sold craft items at a fair. She started the day with $120 in her cash box. During the first hour, she paid a registration fee of $12 and then collected money for three sales of $25, $11, and $37. How much money did she have in her cashbox at the end of the first hour?

Evaluate each expression if x = - 5 , y = - 8 and z = 4 .

15) x + y + z = _____________ *When substituting numbers, put them in

( )!!!!

16) x + 2 z + y = _________

Add the following integers working left to right:

  17) -6 + 8 + - 12 + 15 = ____________

  18) 12 + - 9 + - 16 + 5 = __________

Why do you need to be able to add positive and negative numbers together? Where in life would you use these skills?

p. 68-69

33-44,48-53

Hwk: