2006-08-25 07:27:14 · 8 answers · asked by majinmelinja 1 in Science & Mathematics ➔ Chemistry
If this is for Chemistry, you need to iron out the details with your professor in rounding, because there are two schools of thought on that note.
But teaching significant figures requires more room than what Yahoo! allows, so I'm going to give you UC Berkeley's website tutorial. It will be extremely helpful and less time-consuming.
http://ist-socrates.berkeley.edu/~chem1a/sigfigs/sigfig2.htm
Good luck. If you need help on any problems, I used to tutor Chem and would love to help.
2006-08-25 07:36:43 · answer #1 · answered by kookoonuts 2 · 0⤊ 0⤋
There are several rules for determining the number of significant digits (or significant figures) in a measurement. In general significant figures are determined starting with the leftmost digit.
1. All non-zero digits are significant.
2. The leftmost nonzero digit is the first or most significant figure. For example, in the number 0.02340, the first significant figure is the 2.
3. If there is a decimal point, the rightmost digit is the last or least significant figure. For example, in 0.02340 the first two zeros from the left are not significant but the zero after the 4 is significant.
4. If there is no decimal point explicitly shown, the rightmost non-zero digit is the least significant figure. For example, in 3400 the 4 is the least significant figure since neither zero is significant in this case.
5. All digits between the most significant figure and the least significant figure are significant. For example, 6.07 has three significant figures.
The general rule of thumb in this class is that calculated results can have no more than 3 significant figures (sig figs). This usually means that results shown on a calculator must be rounded off to 3 sig figs.
For example, 252,194,701 would be rounded to 252,000,000.
Sometimes more or fewer than 3 sig figs would be allowed according to the following rules:
MULTIPLICATION or DIVISION
* Keep the same number of sig figs as the factor with the least number of sig figs.
Example: 1.2 x 4.56 = 5.472 on the calculator. But since the one factor has only 2 sig figs, the answer must be rounded to 2 sig figs or 5.5.
ADDITION or SUBTRACTION
* Keep the same number of decimal places as the factor with the least amount.
Example: 1.234 + 5.67 = 6.904 on the calculator. But since the one factor has only 2 decimal places, so must the answer. Thus the result must be rounded to 6.90 (where the zero is significant. See rule 3 above.)
2006-08-25 07:37:59 · answer #2 · answered by Charity 3 · 0⤊ 0⤋
A man told the curator of a museum that the dinosaur bones on display were 230,000,010 years old. The curator asked how he could be so precise. The man said that when he last visited 10 years ago the dinosaur bones were 230,000,000 years old. That joke reveals the secret of significant figures. What makes sense? If you know that the length of a board is 20 to 21 feet long but exactly 10.00 inches wide you can not calculate the surface in square inches any closer than the weakest measurement. Computers will carry far more figures than are significant and it takes judgement in determining where to round off. Perhaps one more decimal place than is justified is in order during hand calculations until you determine the final answer.
2006-08-25 09:50:48 · answer #3 · answered by Kes 7 · 0⤊ 0⤋
An answer can not have more significant figures than any of the measurements used to calculate it.If you measure width at 3.00cm and length at 2.0 cm and height at 1 cm the volume is 6 cm3. It is not 6.0 or 6.00 because the one measurement was only onw significant figure.
2006-08-25 07:35:32 · answer #4 · answered by science teacher 7 · 0⤊ 0⤋
Significant figures are not determined by calculation, rather it is a method of rounding such that all numerical values display the same level of precision which is equal to the level of precision in the least precise number. For example if you were to put the first set of values into signficant figures you would get the second set of values.
Set 1: 3.234, 0.12. 2.01
Set 2 (sig fig): 3.2, 0.12, 2.01
2006-08-25 07:35:07 · answer #5 · answered by hydpalo 2 · 0⤊ 0⤋
When you multiply or divide you round your answer to the smallest amount of sig fig's that were in the original problem. If you add or subtract you round to the smallest number of decimal places.
2006-08-25 07:33:08 · answer #6 · answered by BeC 4 · 1⤊ 0⤋
Would you just take a tiny piece of effort and look it up in your science book?? The rules are there! PS: Forget college, you'll never graduate.
2006-08-25 09:35:00 · answer #7 · answered by MrZ 6 · 0⤊ 0⤋
your q makes no sense- please elaborate
2006-08-25 07:33:27 · answer #8 · answered by laura w 3 · 0⤊ 0⤋