Simple Mathematics

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Why?

afraid.gif (1027 bytes) Why are we afraid of math? It is one of the most useful tools we could ever learn. It's like being afraid of your car. Imagine where you would be without that and you have some idea of what it's like to go through life being afraid of simple math.

Here are some good reasons to learn math:

Math surrounds us. It involves nearly everything we do on a daily basis. Don't believe me? Take this questionnaire.

The Do You Need to Know Math Questionnaire?
If you answer yes to any one of these questions, then you need to know math.

I bet you answered yes to one of those questions. If not then I'm wrong. But regardless, the only really important question to your life right now should be the last one (okay, yes, I'm joking, shopping is important, too). And while I will tell you right here and now that you could still make a decent grade and not know any math, imagine how fine your life will be by knowing a little math!

These math questions are designed to prepare you a little for some of the kinds of math that we will encounter in this course. Rather than wait until we get to those parts of the semester and let you freak out, I'm trying to get the freak going right now so that by the time we get to those important math-oriented sections of the course, you will have calmed down a bit and sharpened your skills enough so that those sections are a piece of cake.

Now, the kind of math you need to know is really quite simple and fairly limited. This isn't a math class. But I hate that deer-in-the-headlights look when I teach tides or waves (one of my favorites and yours) and ask students to 1) add; 2) subtract; 3) multiply; 4) divide; 5) change units; 6) manipulate simple equations. For some reason, many students are simply stunned by these simple math problems.

I'm not going to teach you basic math here. Rather, this section is designed to let you determine whether you need help with math. If you don't understand these simple problems, then seek help. Come talk to me or enroll in a math class. Find a tutor. Buy a basic math book. Please. Don't rob yourself of one of the most powerful tools known to man. You can bet that banks and credit card companies would love it if no one knew math. Don't let them get the best of you.

You will see versions of these math puzzles on virtually every exam. Make sure you work through them and understand them.

Oceanography Math Puzzles

1. You are an ordinary seaman on a ship located at the intersection of the equator and the international date line. You desperately want to move up in ranks because you are tired of cleaning toilets. Your chance comes when the navigator falls overboard while looking at jellyfish. His last words are "One degree of latitude equals 60 nautical miles." A day goes by. The Captain tells you that the ship has sailed sixty (60) nautical miles due east since the tragic accident. If you can tell him the ship's new position, you get the job. What is the ship's new longitude and latitude? (Hint: think about what you need to know to answer this question. Look back through your notes to find the key information.)

2. The Captain, a demanding sort, now wants to know the depth of the water. He gives you a Toys-R-Us Sonar Unit, good enough to report the time it takes a sound pulse to travel from the ship to the bottom and back, but not good enough to calculate the distance. You remember from your oceanography class at Fullerton College that sound travels at approximately 1500 meters per second. You set up the Sonar unit, hit the go button, it pings and 12 seconds later the ping returns. How deep is the bottom in meters?

3. The Captain has an old chart with soundings in miles. Now he wants to know how deep is the bottom in miles. The ship hasn't moved since your first sounding and the ping returns after 12 seconds. How deep is the bottom in miles?

4. The Captain gets a weather report over the weather fax. A storm north of you covers a rectangular area 1000 miles long and 200 miles wide. To learn something about the kinds of waves generated by the storm, the Captain wants to estimate the area over which the storm blows, something known as the fetch. He asks you to calculate the area of the storm given the information in the weather fax. What is the fetch of the storm in square miles?

5. The storm front is approximately 3409 miles due north of the ship. It generates waves traveling due south at 50 feet per second. How many days will it take the waves to reach the ship?

6. The Captain hands you an obscure equation and gives you no clue as to what it means. S=L/T or S equals L divided by T. He asks you to give him a new equation that expresses T in terms of S and L, or T=? What does T equal? (In other words, solve this equation for T.)

7. Woops. He made a mistake. He wants you to solve it for L, or L=? What does L equal, in terms of S and T?

8. The Captain finally reveals to you that this is a speed equation for waves, where S, the speed of the wave is equal to L/T (he won't tell you what they mean!). He reminds you that the waves from the storm are traveling at 50 feet per second and he tells you that T=10 seconds. What does L equal? (Don't forget the units.)

9. The ship finally makes it near shore. The Captain wants to know whether the tides will affect the ship's entry through the harbor. He asks you to compute the difference between the high tide and the low tide. He tells you that the high tide is 6 feet above sea level and that the low tide is 1 foot below sea level (or -1 foot). Compute the difference: 6 - (-1) = ?

10. You finally get off the ship and are dying to go to Vegas but you only have $50 bucks. You can drive your Dodge Dart, which gets 20 miles to the gallon and maxes out at 50 miles per hour; or you can drive your mom's new BMW, which only gets 10 miles to the gallon but goes 150 miles per hour. Gas will cost you a buck a gallon but food will cost you $10 every three hours. Vegas is 400 miles from your port. Which car do you take? Remember, you want the most money possible to gamble in Vegas.

The answers to the Oceanography Math Puzzles will be discussed in the Forums.

More math practice

These web sites have some great and simple math problems that will really help sharpen your math skills. I suggest giving them a try if you felt a little rusty with the above problems. Don't feel bad if you have to venture into lower K-12 to find problems that you can solve. That's what these math lessons are all about. Please feel free to e-mail me if you have any questions.

FunBrain
www.funbrain.com

Girls to the Fourth Power
http://www.stanford.edu/~meehan/xyz/girls4.html

University of Hawaii Quiz Center
www.motted.hawaii.edu

Marmalade_Man's Fantastic Math Tricks
http://www.angelfire.com/me/marmalade/mathtips.html

Dave's Math Tables
http://www.sisweb.com/math/tables.htm

The Math Forum
http://forum.swarthmore.edu/

Frequently Asked Questions about Blackjack
http://conjelco.com/faq/bj.html