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 math 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.*

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