Mth060 Day 2

Sections 1.2 – 1.3

Reading Guides

• Questions• Corrections

Addition with Real Numbers

Section 1.2

Put Calculators Away!!

Signed Numbers

• Signed numbers – positive & negative numbers.

• Absolute value is the distance the number is from zero.

• Addition – Find the SUM• When finding a SUM:

( ) ( ) a positive answer

( ) ( ) a negative answer

( ) ( ) ?? depends on which number has the larger absolute value

Example #1

• You have $5 in the checking account and deposit $25 – How much in the account now?

• You owe someone $5 and borrow $25 more – How much do you owe now?

• You have $100 in the bank. You make a withdrawal of $20 – How much in the account now?

Example #2

• Find the SUM:

• Find the SUM:

17 18

8 ( 6)

11 9

100 ( 25)

Try it…

• Find the SUM: 24 ( 16)

12 ( 17)

2.1 ( 4.6)

35 75

9 ( 6) 5

Summary 1.2 – slide 7

Subtraction with Real Numbers

Section 1.3

Subtraction →→ DIFFERENCE

• You are standing on the cliff above Death Valley.

• The cliff’s elevation is 200 feet above sea level.• Your favorite super ball falls over the edge and

lands on the floor of the valley at it’s lowest elevation, which 282 feet below sea level.

• What is the elevation drop of the super ball?• How do we show this mathematically?

Additive Inverse

• Definition:

• Example with numbers:

( ) 0a a

13 ( 13) 0

Same thang!

• Subtraction and negative sign confusion…

5 ( 6) 5 6 11

( )a b a b

8 ( 10) 8 10

Example #1

• Change in value = End value - beginning value• According the NASA, the average temperature

on the Earth’s moon during the day 260⁰F and during the night is -280⁰F. What is the daily temperature change on the moon?

Example #2

• Pop culture artist Michael Jackson was born in August 1958 and died in June 2009. How old was he when he died? (Notice he did not reach his 2009 birthday.)

Try it…

• Find the DIFFERENCE: 4 6

18 17

11 5

3 ( 8)

2.8 ( 3.1)

Try it…

Summary

• Due Date Sheet• Quiz #1 Due Friday (FIRM)– Taken in SMART Lab– Lab Closes at 4 PM

• Reading Guides for Day #3– Sections 1.4 & 1.8– On Blackboard

Coming up…

• Quiz #1 – Due by Friday (SMART Lab 4PM)• Reading Guide for Day 3: – Instruct Sections• 1.4 Mult/Div Real Numbers• 1.8 Order of Operation

– Email kcaligure@cocc.edu if you have any problem getting into Blackboard – I will send a copy

Exit Ticket

1. Find the SUM:

2. Find the DIFFERENCE:

3. At 2 PM the temperature was 76⁰F. At 8 PM the temperature was 58 ⁰F. what was the change in termperature?

18 ( 25)

250 ( 36)