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Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
1

Why are we doing this assignment?
It is important that we review some basic math principles before we start doing formulas in Excel spreadsheets. This assignment will review the math and business concepts you will need to know to complete the rest of the spreadsheet assignments we will do in class.
Reach each slide carefully and do the examples on the handout as you play this slide show.
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Symbols for math operations

The symbols we will use for this assignment (and in Excel) to perform math operations are:

+ for addition



for subtraction
* for multiplication
/ for division
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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1. Order of Operations



Formulas in Excel follow the regular order of operations.
Order of operations refers to the order which operations in a mathematical formula should be performed.
Here is the order:


You should always perform the operations in parentheses ( ) first, left to right
Then do multiplication and division, left to right

Then do addition and subtraction, left to right
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Example

To solve the problem 3*3 + (15-5) /2 -2

First solve 15-5 because it is in parentheses – so we now have 3*3+10/2-2


Next we will do the multiplication and division, so we now have 9+5-2
Now we can do the addition and subtraction and our final answer is 12
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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
Do the three examples on your handout and write the correct answers on your handout:

2 + 7 * 8 / 2 – 10 = 20

10 – (24+9) * 2 = -56

120 / 3 + 20 * 2 – 5 = 75
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Answers

The correct answers for the examples are:

20


-56
75
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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2. Average

To find the average of a group of numbers, add the numbers together and then divide by the number of items in the group.

To find the average of these numbers
8, 12, 3, 10, 5, 4
Add the numbers together which equals 42
There are 6 numbers so we will divide 42 by
6 and the average of these 6 numbers is 7
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Examples

Do the two examples on your handout and write the correct answers on your handout:

Find the average of $36, $49, $22, $48, $39,
$40, and $18 36

Find the average of 3.2, 4.2, 9.25, 5, 7.1, 9.8, and 12.4: 7.28
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Answers

The correct answers for the examples are:

36

7.28
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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3. Percent


To find a percentage of a number, write the percent as a decimal then multiply the number by the decimal.
To find out 35% of 90
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

Convert the percent to a decimal which is .35
Then multiply .35*90
31.5 is 35% of 90
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Examples

Do the three examples on your handout and write the correct answers on your handout:

25% of 384 96


21% of 54
85% of 400
11.34
340
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Answers

The correct answers for the examples are:

96


11.34
340
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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4. Payroll


Payroll is determining how much an employer is to pay his employees for the work they have done.
A person who is paid by the hour works for an hourly rate which is a certain amount of money for each hour that is worked. The total amount of money that an employee is paid is called GROSS PAY .
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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4. Payroll


To calculate gross pay, multiply the hourly rate by the number of hours worked :
Hourly Rate * Hours Worked
If you have a job and your hourly rate is
$7.55 and you work 25 hours in one week your gross pay would equal:
7.55*25 = $188.75
Your GROSS PAY is $188.75
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Examples

Do the two examples on your handout and write the correct answers on your handout:

Cassie earns $16.25 an hour. What is her gross pay for last week if she worked 25 hours?
$406.25

Mark is paid $9.10 an hour. He worked 38 hours last week. What is his gross pay?
$345.80
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Answers

The correct answers for the examples are:

$406.25

$345.80
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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4. Payroll continued

DEDUCTIONS are subtractions from gross pay. The federal government as well as states require employers to deduct money from employee wages for income taxes, social security, and Medicare taxes.
The amount of money withheld or deducted depends on the gross pay and the number of dependents (spouse and children) the employee has. Deductions for taxes are usually about 30% of the amount of gross pay.
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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4. Payroll continued

To calculate deductions for this assignment you will multiply the gross pay by 30%:

Gross Pay * .30
If your gross pay is $188.75, the total amount that would be deducted from your paycheck would be:
188.75 * .30 = $56.63
Your total deductions would be $56.63
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Examples

Do the two examples on your handout and write the correct answers on your handout:


Based on Cassie’s gross pay above, approximately what amount will be deducted for taxes: $121.88
Based on Mark’s gross pay above, approximately what amount will be deducted for taxes:
$103.74
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Answers

The correct answers for the examples are:

$121.88

$103.74
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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4. Payroll continued

After all deductions are subtracted from gross pay, the amount that remains is called NET PAY . Net pay is the actual amount the employee will be paid on their paycheck.
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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4. Payroll continued


To calculate net pay, you subtract the total amount of deductions from gross pay:
Gross Pay – Deductions
If your gross pay is $188.75 and your deductions are $56.64 your net pay would be:
188.75 – 56.63 = 132.12
Your net pay would be $132.12
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Examples

Do the two examples on your handout and write the correct answers on your handout:

What is Cassie’s net pay?
$284.37

What is Mark’s net pay?
$242.06
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Answers

The correct answers for the examples are:

$284.37

$242.06
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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5. Sales Tax
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
In most states, when you purchase items from a store, you pay the price of the item plus SALES TAX .
Sales tax is a percentage of the total cost of the items you purchase. In Utah, the sales tax rate is 6.6% or .066.
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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5. Sales Tax continued


To calculate sales tax you will multiply the purchase amount by the tax rate:
Purchase Amount * Tax Rate
If you purchase items that total $25 in
Utah the amount of sales tax you will pay is:
25 * .066 = 1.65
Your amount of sales tax would be $1.65
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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5. Sales Tax continued


To find the total amount you will pay for the items you add the purchase amount to the amount of sales tax:
Purchase Amount + Amount of Sales Tax
If the purchase amount is $25 and the amount of sales tax is $1.65 the total amount you would pay is:
25 + 1.65 = 26.65
The total amount would be $26.65
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Examples

Do the two examples on your handout and write the correct answers on your handout
(use .066 for the tax rate):

A customer buys items with a total purchase price of $72. What is the amount they will pay for these items with sales tax?

A customer buys items with a total purchase price of $37. What is the amount they will pay for these items with sales tax?
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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Answers

The correct answers for the examples are:


$76.75
$39.44
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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This is the end of the slide show. Now complete the problems on the handout.
You may use a calculator – you can use your own calculator or the calculator on your computer (START button, All
Programs, Accessories). You can close this slide show and finish the assignment.
Computer Tech - Business Math Review -
K. Parsons - Revised 8/2010
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