Sunday, June 07, 2009
In picture Borobudur,there are many circles with different diametre.
Wednesday, May 20, 2009
Active Study Math
Be actively involved in managing the learning process, the mathematics and your study time:
1. Take responsibility for studying, recognizing what you do and don't know, and knowing how to get your Instructor to help you with what you don't know.
2. Attend class every day and take complete notes.
Instructors formulate test questions based on material and examples covered in class as well as on those in the text.
3. Be an active participant in the classroom. Get ahead in the book; try to work some of the problems before they are covered in class. Anticipate what the Instructor's next step will be.
4. Ask questions in class! There are usually other students wanting to know the answers to the same questions you have.
5. Go to office hours and ask questions. The Instructor will be pleased to see that you are interested, and you will be actively helping yourself.
6. Good study habits throughout the semester make it easier to study for tests.
Studying Math is Different from Studying Other Subjects
a. Math is learned by doing problems. Do the homework. The problems help you learn the formulas and techniques you do need to know, as well as improve your problem-solving prowess.
b. A word of warning: Each class builds on the previous ones, all semester long. You must keep up with the Instructor: attend class, read the text and do homework every day. Falling a day behind puts you at a disadvantage. Falling a week behind puts you in deep trouble.
c. A word of encouragement: Each class builds on the previous ones, all semester long. You're always reviewing previous material as you do new material. Many of the ideas hang together. Identifying and learning the key concepts means you don't have to memorize as much.
College Math is Different from High School Math
A College math class meets less often and covers material at about twice the pace that a High School course does. You are expected to absorb new material much more quickly. Tests are probably spaced farther apart and so cover more material than before. The Instructor may not even check your homework.
1. Take responsibility for keeping up with the homework. Make sure you find out how to do it.
2. You probably need to spend more time studying per week - you do more of the learning outside of class than in High School.
3. Tests may seem harder just because they cover more material.
You may know a rule of thumb about math (and other) classes: at least 2 hours of study time per class hour. But this may not be enough!
1. Take as much time as you need to do all the homework and to get complete understanding of the material.
2. Form a study group. Meet once or twice a week (also use the phone). Go over problems you've had trouble with. Either someone else in the group will help you, or you will discover you're all stuck on the same problems. Then it's time to get help from your Instructor.
3. The more challenging the material, the more time you should spend on it.
Problem Solving (Homework and Tests)
The higher the math class, the more types of problems: in earlier classes, problems often required just one step to find a solution. Increasingly, you will tackle problems which require several steps to solve them. Break these problems down into smaller pieces and solve each piece - divide and conquer!
1. Problems testing memorization ("drill"),
2. Problems testing skills ("drill"),
3. Problems requiring application of skills to familiar situations ("template" problems),
4. Problems requiring application of skills to unfamiliar situations (you develop a strategy for a new problem type),
5. Problems requiring that you extend the skills or theory you know before applying them to an unfamiliar situation.
In early courses, you solved problems of types 1, 2 and 3. By College Algebra you expect to do mostly problems of types 2 and 3 and sometimes of type 4. Later courses expect you to tackle more and more problems of types 3 and 4, and (eventually) of type 5. Each problem of types 4 or 5 usually requires you to use a multi-step approach, and may involve several different math skills and techniques.
When you work problems on homework, write out complete solutions, as if you were taking a test. Don't just scratch out a few lines and check the answer in the back of the book. If your answer is not right, rework the problem; don't just do some mental gymnastics to convince yourself that you could get the correct answer. If you can't get the answer, get help.
The practice you get doing homework and reviewing will make test problems easier to tackle.
Tips on Problem Solving
Apply Pólya's four-step process:
The first and most important step in solving a problem is to understand the problem, that is, identify exactly which quantity the problem is asking you to find or solve for (make sure you read the whole problem).
Next you need to devise a plan, that is, identify which skills and techniques you have learned can be applied to solve the problem at hand.
Carry out the plan.
Look back: Does the answer you found seem reasonable? Also review the problem and method of solution so that you will be able to more easily recognize and solve a similar problem.
Some problem-solving strategies: use one or more variables, complete a table, consider a special case, look for a pattern, guess and test, draw a picture or diagram, make a list, solve a simpler related problem, use reasoning, work backward, solve an equation, look for a formula, use coordinates.
"Word" Problems are Really "Applied" Problems
The term "word problem" has only negative connotations. It's better to think of them as "applied problems". These problems should be the most interesting ones to solve. Sometimes the "applied" problems don't appear very realistic, but that's usually because the corresponding real applied problems are too hard or complicated to solve at your current level. But at least you get an idea of how the math you are learning can help solve actual real-world problems.
Solving an Applied Problem
First convert the problem into mathematics. This step is (usually) the most challenging part of an applied problem. If possible, start by drawing a picture. Label it with all the quantities mentioned in the problem. If a quantity in the problem is not a fixed number, name it by a variable. Identify the goal of the problem. Then complete the conversion of the problem into math, i.e., find equations which describe relationships among the variables, and describe the goal of the problem mathematically.
Solve the math problem you have generated, using whatever skills and techniques you need (refer to the four-step process above).
As a final step, you should convert the answer of your math problem back into words, so that you have now solved the original applied problem.
Studying for a Math Test
Everyday Study is a Big Part of Test Preparation
Good study habits throughout the semester make it easier to study for tests.
Do the homework when it is assigned. You cannot hope to cram 3 or 4 weeks worth of learning into a couple of days of study.
On tests you have to solve problems; homework problems are the only way to get practice. As you do homework, make lists of formulas and techniques to use later when you study for tests.
Ask your Instructor questions as they arise; don't wait until the day or two before a test. The questions you ask right before a test should be to clear up minor details.
Studying for a Test
· Start by going over each section, reviewing your notes and checking that you can still do the homework problems (actually work the problems again). Use the worked examples in the text and notes - cover up the solutions and work the problems yourself. Check your work against the solutions given.
· You're not ready yet! In the book each problem appears at the end of the section in which you learned how do to that problem; on a test the problems from different sections are all together.
Step back and ask yourself what kind of problems you have learned how to solve, what techniques of solution you have learned, and how to tell which techniques go with which problems.
Try to explain out loud, in your own words, how each solution strategy is used (e.g. how to solve a quadratic equation). If you get confused during a test, you can mentally return to your verbal "capsule instructions". Check your verbal explanations with a friend during a study session (it's more fun than talking to yourself!).
Put yourself in a test-like situation: work problems from review sections at the end of chapters, and work old tests if you can find some. It's important to keep working problems the whole time you're studying.
Start studying early. Several days to a week before the test (longer for the final), begin to allot time in your schedule to reviewing for the test.
Get lots of sleep the night before the test. Math tests are easier when you are mentally sharp.
Taking a Math Test
Test-Taking Strategy Matters
Just as it is important to think about how you spend your study time (in addition to actually doing the studying), it is important to think about what strategies you will use when you take a test (in addition to actually doing the problems on the test). Good test-taking strategy can make a big difference to your grade!
Taking a Test
First look over the entire test. You'll get a sense of its length. Try to identify those problems you definitely know how to do right away, and those you expect to have to think about.
Do the problems in the order that suits you! Start with the problems that you know for sure you can do. This builds confidence and means you don't miss any sure points just because you run out of time. Then try the problems you think you can figure out; then finally try the ones you are least sure about.
Time is of the essence - work as quickly and continuously as you can while still writing legibly and showing all your work. If you get stuck on a problem, move on to another one - you can come back later.
Work by the clock. On a 50 minute, 100 point test, you have about 5 minutes for a 10 point question. Starting with the easy questions will probably put you ahead of the clock. When you work on a harder problem, spend the allotted time (e.g., 5 minutes) on that question, and if you have not almost finished it, go on to another problem. Do not spend 20 minutes on a problem which will yield few or no points when there are other problems still to try.
Show all your work: make it as easy as possible for the Instructor to see how much you do know. Try to write a well-reasoned solution. If your answer is incorrect, the Instructor will assign partial credit based on the work you show.
Never waste time erasing! Just draw a line through the work you want ignored and move on. Not only does erasing waste precious time, but you may discover later that you erased something useful (and/or maybe worth partial credit if you cannot complete the problem). You are (usually) not required to fit your answer in the space provided - you can put your answer on another sheet to avoid needing to erase.
In a multiple-step problem outline the steps before actually working the problem.
Don't give up on a several-part problem just because you can't do the first part. Attempt the other part(s) - if the actual solution depends on the first part, at least explain how you would do it.
Make sure you read the questions carefully, and do all parts of each problem.
Verify your answers - does each answer make sense given the context of the problem?
If you finish early, check every problem (that means rework everything from scratch).
Get help as soon as you need it. Don't wait until a test is near. The new material builds on the previous sections, so anything you don't understand now will make future material difficult to understand.
Use the Resources You Have Available
Ask questions in class. You get help and stay actively involved in the class.
Visit the Instructor's Office Hours. Instructors like to see students who want to help themselves.
Ask friends, members of your study group, or anyone else who can help. The classmate who explains something to you learns just as much as you do, for he/she must think carefully about how to explain the particular concept or solution in a clear way. So don't be reluctant to ask a classmate.
Go to the Math Help Sessions or other tutoring sessions on campus.
Find a private tutor if you can't get enough help from other sources.
All students need help at some point, so be sure to get the help you need.
Don't be afraid to ask questions. Any question is better than no question at all (at least your Instructor/tutor will know you are confused). But a good question will allow your helper to quickly identify exactly what you don't understand.
Not too helpful comment: "I don't understand this section." The best you can expect in reply to such a remark is a brief review of the section, and this will likely overlook the particular thing(s) which you don't understand.
Good comment: "I don't understand why f(x + h) doesn't equal f(x) + f(h)." This is a very specific remark that will get a very specific response and hopefully clear up your difficulty.
Good question: "How can you tell the difference between the equation of a circle and the equation of a line?"
Okay question: "How do you do #17?"
Better question: "Can you show me how to set up #17?" (the Instructor can let you try to finish the problem on your own), or "This is how I tried to do #17. What went wrong?" The focus of attention is on your thought process.
Right after you get help with a problem, work another similar problem by yourself.
You Control the Help You Get
Helpers should be coaches, not crutches. They should encourage you, give you hints as you need them, and sometimes show you how to do problems. But they should not, nor be expected to, actually do the work you need to do. They are there to help you figure out how to learn math for yourself.
When you go to office hours, your study group or a tutor, have a specific list of questions prepared in advance. You should run the session as much as possible.
Do not allow yourself to become dependent on a tutor. The tutor cannot take the exams for you. You must take care to be the one in control of tutoring sessions.
You must recognize that sometimes you do need some coaching to help you through, and it is up to you to seek out that coaching.
Department of Mathematics and Computer Science
SAINT LOUIS UNIVERSITY,June 1993
Saturday, April 19, 2008
The first computer was called the ENIAC, which was built during World War II. Computers first utilized vacuum tubes and were very large (sometimes room size) and only found in businesses, schools, or governments. Later, computers began utilizing transistors as well as smaller and cheaper parts that allowed the common person to own their own computer. This history of computers and related topics can be found on our history page.
Today, most computers are often comprised with some or all of the below components.
Types of computers:
There are several types of computers, below is a listing of some of the major types of computers you're most likely to encounter.
- Embedded computers - The most commonly found and used computer. An embedded computer is a computer with a specific function found in such things as cars, microwaves, TVs, the VCR, and other home electronics.
- Personal computer - As shown above the personal computer is the most widely used computer today and most likely what you're using now. Personal computers are available in two different brands IBM compatible (often referred to as PC) and Apple Macintosh computers.
- Laptop / Portable computer - Another commonly used computer, a laptop or portable computer is a small computer that users can easily carry around and work with when on the road or elsewhere.
- Server - A powerful computer that is often set aside to perform a specific task. For example, a web server is one or more computers responsible for handling the data for a website and the users visiting it.
- Mainframe or Supercomputer - Often large computers or a collection of smaller computers working as a large computer to perform extremely complicated tasks such as receiving and displaying and understanding weather patterns.
Mathematics Content Areas for student
The committee identified four major content areas. The original statement from the committee was a bit more terse, but we now identify the four areas as follows:
- 1.Logic, Critical Thinking, and Problem Solving: Students should learn skills that will enable them to construct a logical argument based on rules of inference and to develop strategies for solving quantitative problems.
- 2.Number Sense and Estimation: Students should become "numerate," or able to make sense of the numbers that confront them in the modern world. For example, students should be able to give meaning to a billion dollars, and distinguish it from a million dollars or a trillion dollars. Part of developing such number sense involves making simple calculations or estimates to put numbers in perspective. As a simple example, a student should be able to quickly figure out that a star athlete earning $10 million per year earns about 400 times more than the average American.
- 3.Statistical Interpretation and Basic Probability: Reports about statistical research (for example, concerning diet or disease) are ubiquitous in the news. Students must have the stools needed to interpret this research. Note the emphasis on interpretation. While it is certainly useful to show students how to calculate a mean, a standard deviation, or a margin of error, our non-SEM students will rarely perform such calculations once they leave our course. But they will encounter such statistics in the news, and we must equip them to interpret these statistics critically. Because statistical interpretation involves inference from samples to populations, it also requires a basic understanding of probability. This study of probability can then be easily extended to relevant topics including lotteries, casino gambling, risk assessment, and disease and drug testing.
- 4.Interpreting Graphs and Models: Graphical displays of numbers abound in modern media, so learning how to create and interpret graphs is clearly important. Though it is a bit less obvious, an understanding of modeling is equally important, because many major issues today (such as economic or environmental issues) are studied through mathematical models. While we do not expect non-SEM students to create sophisticated mathematical models, we must teach them how to interpret what they read or hear about models. For example, they should know enough to question the assumptions of a model before accepting its predictions, and they should understand the difference between linear and exponential growth. We group graphing and modeling together because we have found that one of the easiest ways to teach students about modeling is by presenting graphs as simple mathematical models.