grantham.edu | 1 (800) 947-2684
Topics

### Subscribe via E-mail

Search the Blog

Welcome to the Grantham University Blog! The purpose of this blog is to offer helpful resources to future, current and former online students wanting to excel in the distance learning environment and thrive in a competitive workplace. Visit us every day for fresh posts.

# Grantham University Blog

### 4 Practical Ways to Use Mathematics in Everyday Life

Many people, including students in online degree programs, seem to despise and/or fear math. Those emotions may be understandable for people who have suffered unfortunate experiences in their schooling (something different than true education). Nonetheless, the practical application, and therefore the knowledge, of elementary mathematics is indispensable in everyday life. Below are four such uses:

1. Computing mentally how much money to leave as a tip in a restaurant.

It is customary in most restaurants nowadays to leave a tip in the amount of 15-20 percent of the cost of one’s meal. A simple way to compute a tip of 15-20 percent derives from finding one-tenth of the cost of the meal. For example, if the cost of the meal is \$38.27, then one-tenth rounded is about \$3.83 – let’s say \$3.80. Half of this is \$1.90 and doubling it would take you to \$7.60.

Therefore:

• A 15 percent tip would be about \$3.80 (10 percent), plus \$1.90 (5 percent), or \$5.70.
• A 20 percent tip would be \$7.60 (\$3.80 doubled).

2. Counting back change after a purchase.

This is a lost skill nowadays since the computerized cash register tells one how much change to give a customer after a purchase. However, this skill can be used to tell quickly whether you have received the correct amount of change after a purchase.

For example, suppose that you purchase your favorite fast-food meal for \$6.67 and you pay with a \$10 bill. In the old days, your change would be counted back to you as follows: \$6.67 plus 3 cents makes \$6.70; \$6.70 plus a nickel makes \$6.75; \$6.75 plus a quarter makes \$7; \$7 plus three dollar bills make \$10. This process shows that the customer who pays \$10 receives \$10, in effect, in return, but \$6.67 is in the form of goods and the rest is change.

3. How much is \$1 trillion dollars?

The size of the federal government debt and deficit is measured in trillions of dollars nowadays. Such amounts are so unimaginably large that a visual representation may help one to understand the magnitude of a debt of this size. Consider that 250 crisp, new bills of any denomination will form a stack one inch high. Thus, a one-inch stack of \$100 bills will constitute \$25,000 (250 x 100). A stack of \$100 bills, 40 inches tall would then be \$1 million (25,000 x 40). Now, since 1 trillion (1 followed by 12 zeros) is 1 million x 1 million, we would need a stack of \$100 bills 40 million inches high. This is a stack over 630 miles tall!

4. Using the World Clock to determine the time required to fly from one city to another across time zones.

With such Web sites as travelocity.com, travel agents are rarely necessary anymore. One can search for almost any possible flight online and make reservations directly. Sometimes the itinerary shows not only the times of departures and arrivals for all flights, but the length in time (and miles) of such flights.

When such information isn’t provided, however, the World Clock can be used to determine how long a flight takes when the departure city and the arrival city are in different time zones.

For example, a flight from Moscow, Russian Federation, to Kiev, Ukraine, shows the following: 8 a.m. is the departure time and 7:40 a.m. is the arrival time.

Yes, you read that correctly. The flight departs at 8 a.m. and arrives at 7:40 a.m. How is that possible? Time travel is not possible, as far as anyone knows!

The World Clock shows that Moscow, Russian Federation, is two hours ahead of Kiev. So when the flight departs at 8 a.m., Moscow time, it actually arrives at 9:40 a.m., Moscow time (7:40 a.m., Kiev time). Thus, the flight takes one hour and 40 minutes, not -20 minutes as the time traveler would experience.

There are many more routine applications of mathematics beyond these four simple examples. Perhaps those who fear mathematics can begin to view it for what they know and can apply, instead of what they don’t know. Everyone must start with what they know. Learning math can be enjoyable and satisfying, even when it is hard work. That can, of course, be said about learning most anything of value.

Photo credit: stock.xchng

About the Author: Peter McCandless is a full-time Mathematics instructor at Grantham University. He teaches in the College of Arts and Sciences.

Wow! Great blog! I learned a lot from these four tips! Number 3 was really interesting, and 1& 2 happens to me all the time,but never really take the time to think abou it.
Posted @ Monday, February 20, 2012 10:33 AM by Michael Bermudez
I like the first two "Practical Math Usage", but instead of the last two, I would recommend.

3. Write down the odometer at each fill-up at gas station, then the amount of gallons needed at next fill-up to figure your Miles-per-gallon (MPG). This simple trick can identify problems and can be used to help adjust your driving skills to increase mileage.
Posted @ Monday, February 20, 2012 10:39 AM by Brian Schehl
I have flown from Atlanta, GA to Tokyo Japan many times. A few times I arrived before I left!
Posted @ Monday, February 20, 2012 1:06 PM by Jim Marion
How to calculate Pi to 23 places (Geometry)

We calculate using mnemonics (words) to memorize PI.

Remembering PI can be as simple as reading this short paragraph…

For example;

To translate:
“3.14159265358979323846264”

Then learn this short paragraph.

“How I want a drink, alcoholic of course, after the heavy lectures involving quantum mechanics. All of thy geometry, Herr Planck, is fairly hard.”

The trick is that the numbers are hidden within the words. Count each letter to find the number such as, How (3) I (1) want (4) a (1) drink (5) alcoholic (9) of (2) course (6) and so on …

Once you find all 23 numbers this will impress your friends.

Order of calculations in math (Algebra)

Ever wonder how to calculate this simple expression 2 x (3+4)

Believe it or not there is an order, an arrangement, or an organizational skill in which you have to begin in order to solve the expression.

Again, we calculate using mnemonics (words) to memorize the order.

We use: Please Excuse My Dear Aunt Sally

Translated order meaning:

Parentheses, Exponents, Multiplication, Division, Addition, Subtraction

Therefore, starting from left to right we must first begin solving what is inside the parenthesis. Next, we solve the exponents. Third, is multiplication or division and lastly we add or subtract.

Finally, to solve our expression …

1. (3+4) = 7 //We solve within parenthesis first, ok
2. 2 x 7 = 14 //We multiply since we don’t have exponents and
multiply and division is next within the order

Sine? Cosine? Tangent? (Trig)

We calculate using mnemonics (words) to memorize the law of sines.

SOH …CAH … TOA (pronounced "so - ka - toe - ah").

The SOH stands for "Sine of an angle is Opposite over Hypotenuse."

S= O/H

The CAH stands for "Cosine of an angle is Adjacent over Hypotenuse."

C=A/H

The TOA stands for "Tangent of an angle is Opposite over Adjacent."

T=O/A

<a>http://www.themathlab.com/writings/short%20stories/sohcahtoa/overview.htm

There are more to be found and more to be shared with us all.
Posted @ Monday, February 20, 2012 2:13 PM by Chris Correll
:) an avid fan of different mathematical techniques.. thanks for this post.bookmarked this just in case :)
Posted @ Sunday, February 26, 2012 10:14 AM by kimi
thanks for the help
Posted @ Thursday, February 21, 2013 4:34 AM by simran
 Post Comment Name  * Email  * Website (optional) Comment  * Allowed tags: link, bold, italics Receive email when someone replies. Subscribe to this blog by email.
Grantham University
7200 NW 86th Street, Kansas City, MO 64153
1-888-Y-GRANTHAM | Fax 816-595-5757