How to aviod careless mistakes?

[Shing]

Hi guys,
I am a sophomore

I am having a trouble that I often make careless mistakes,
and it caused me directly losing up to 50% of the score in some course. (I know the concept, I'd worked on the P-sets, I'd reviewed...)

I want to ask if there is anyway to improve?
by doing some simple P-set? (the bad news is that time is really not enough...)

Thank you so much!

 

[Shing]

For an example,
Sometimes, I miss the square two when I start to calcule the K.E. :(

 

[Rasalhague]

If worst comes to worst...

http://www.wellcome.ac.uk/News/2010/News/WTX063325.htm

 

[Mark44]

For an example,
Sometimes, I miss the square two when I start to calcule the K.E. :(

If you're writing (1/2)mv instead of (1/2)mv², it sounds like putting in some more time memorizing the most important formulas is called for.

As far as making careless mistakes, try to budget your time (if you're taking a test) so that you have a few minutes to go back over your work. Most of us make careless mistakes from time to time, and going through the work again can help us find at least some of them.

In a timed-test situation, you'll need to choose between trying to work through all the problems (with no time to review your work) or doing as many as you can, but leaving a few minutes to take another look at your work. If you tend to make a lot of mistakes, the second option might be the better one.

 

[symbolipoint]

Organize your concepts and your set of formulas.

Determine in exercise problems or items, what information (numbers) are known and what is unknown. Set-up your equations and any drawings (usually from which you will use to find your expressions and equations); solve symbolically. Leave your final numeric answer, if any, for last --- in other words, substitute the known values for final answer AFTER first solving the problem symbolically.

Analyzing and setting up the solution is more important than reporting a final answer.

 

[Sniperman724]

What helps for me is to always check your work every few lines just to make sure that you haven't made any mistakes. And also try not to rush on the work too because that is when people tend to make stupid mistakes the most.

 

[Mentallic]

Answer lots and lots of questions.

 

[zorro]

Practice makes a man perfect!

 

[Shing]

haha thanks!
Actually, I memorised the Work-theorem correctly, but when I was calculating the real value of it, I just missed the sqare... :(

Besides, I just realize that getting a physical feeling on the answer work now and then.
Also, on the other hand, I am learning how to write a clean and clear calculation on the paper. Thanks anyway again! :D

 

[jasonRF]

haha thanks!

Also, on the other hand, I am learning how to write a clean and clear calculation on the paper. Thanks anyway again! :D

Yes that can be part of it, but the other poster's recommendations of solving tons of problems and practice are real keys. When I TA'd I realized that many students who scored poorly simply had poor algebra skills. Couldn't do a half dozen lines of algebra without a mistake. Practice, practice practice. Start out going as slow as you need to in order to reliably not make mistakes. Keep practicing, gradually getting faster, until you can do it fast without making mistakes. I don't think there is any other way than discipline and hard work.

Wow, I sound like my dad!

good luck!

jason

 

[D H]

Learn to do things in a way that help keep errors from popping up in the first place, learn to do things that help you see that you have made an error, and learn where you do make mistakes so that you can pay extra attention in those error-prone situations.Practice and knowing the key underlying principles will help keep your error rate low. Note that I said knowing, not memorizing. There is a big difference between the two. You do need to resort to memorization to some extent because perpetually going back to first principles takes too much time. Knowing the underlying principles helps reduce the amount of material that needs to be memorized.

Some simple tricks can help a lot in detecting errors. A memory glitch might well lead you to write that KE=½mv rather than ½mv². A quick check of the units will tell you that the former is incorrect. Learn dimensional analysis. Don't just write down numerical values in some equation. Write down the units as well and carry them along as part of the calculations. Tedious? Practice makes it easier. Learn to work symbolically, inserting the numeric values late in the game.

Learn to recognize nonsense. It looks like your calculations are leading to a negative mass or negative temperature: Backtrack. Find your stupid mistake. We all make stupid mistakes. Developing the ability to catch the kinds of stupid mistakes you are prone to make is an important skill.