Mth060 Day 3

Sections 1.4 & 1.8

Multiplication & Division with Real Numbers

Section 1.4

Operations with Signed Numbers

• Rules for Add/Subtract different than Mult/Div• Addition – Find the SUM• Subtraction – Find the DIFFERENCE• Multiplication – Find the PRODUCT• Division – Find the QUOTIENT• Handout – REFERENCE SHEET

Ways to Write Multiplication

• Same Thang!

• NOT the Same Thang!

3 ( 5) 3 ( 5) (3)( 5) 3( 5)

3( 5) 3 (5)

Multiplication by Zero

• Everything MULTIPLIED by zero is (=) zero

9(3)(0)( 10)

Ways to Write Division

• Same Thang!

• Something to MEMORIZE!

• Check this out on your calculator

11 2 1/ 2

2

00 but

0

aundefined

a

Same Thang!

• Where do I put the negative sign?

• NOT THE SAME THANG!

3 3 3

16 16 16

3 3

16 16

Example #1 – Find the Product

3( 4)

( 6)(5)

13( 2)

3(2)( 3)

7( 16)(0)

True/False

( 7) 0 ( 7)(0)

( 4)(9) ( 24) ( 12)

7 8 ( 10) ( 5)

Average aka Mean

• Average Defined: the average of a SET of numbers is the sum of the set of numbers divided by the number of numbers in the set.

Example #2

Fifteen students scored the following scores on an exam in Algebra I:

1 scored 67, 4 scored 73, 3 scored 77, 2 scored 80, 3 scored 88, and 2 scored 93.

What was the average score for these students?

Try it…

Find the mean of the following set of integers:-10, 15, 16, -17, -34, and -42

Order of Operation

Section 1.8

Rules for Order of Operations

1. Simplify within grouping symbols parentheses ( ), brackets [ ], and braces { }, working from the innermost grouping outward.

2. Evaluate exponents.3. Moving LEFT to RIGHT, perform multiplication

OR division.4. Moving LEFT to RIGHT, perform addition OR

subtraction.

PEMDASMnemonic to remember order:

• Parentheses• Exponents• Multiplication OR Division (caution: left to

right)• Addition OR Subtraction (caution: left to right)

More examples of “grouping symbols”

• Fractions:

• Absolute Values:

• Roots:

4 74 7

10 1 10 1

| 3 5 |

6 14

Example #1

Use the Order of Operations to evaluate the expression:

9 6[( 21) 7(2) ( 8)]

223 3

3 44 2

Try it… Use the Order of Operation to evaluate the expression:

15 3 3 10

2 26 13 15 8 2 3 1

Summary

• Syllabus• Reference sheet• Multiplication/Division Rules versus

Addition/Subtraction Rules• Combine it all together with Order of

Operation: PEMDAS

Coming up…

• Due Dates• Quiz #2 Due Friday (RECALL: includes

problems from Day 1 forward)– Taken in SMART Lab– Lab Closes at 4 PM on Fridays

• Reading Guides for Day #4– Sections 2.1a-b– On Blackboard

Exit Ticket

1. Find the SUM:

2. Find the DIFFERENCE:

3. Find the PRODUCT:

4. Find the QUOTIENT:

18 ( 25)

250 ( 36)

( 6) 3 2

30

5