Scientific Figures..? ?

Question

I was wondering if you could explain to me about how to figure out Scientific Figures. I have a tset tommorrow and my teacher did a really bad explaination of it.

Thank You (:

Answer 1

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Well, you've got two different terms combined here.

There's scientific notation:

Given:

1,500,000

In scientific notation:

1.5 x 10^6

To convert a number from "normal" notation to scientific notation, move the decimal to the right of the left most non-zero digit. If to do this you moved to the left, the exponent on x 10 (times 10) is positive and equivalent to the number of spaces you moved the decimal. If to do this you moved to the right, the exponent on x 10 is negative and equivalent to the number of spaces you moved the decimal.

Significant figures:

When adding or subtracting:

10.79 + 1.983 = 12.773, but you only have 2 significant figures after the decimal, so the answer rounds to 12.77.

You use the smaller number of decimal places.

10.79 - 1.983 = 8.807, must be rounded to 2 decimal places, so, 8.81

When multiplying or dividing:

1.2 x 3.983 = 4.7796

1.2 has 2 significant figures

3.983 has 4 significant figure

Use the fewer number of sig figs in your answer

Answer becomes: 4.8 (4.7796 rounded to 2 sig figs)

1.200 has 4 sig figs

3.983 has 4 sig figs

1.200 x 3.983 = 4.7796 Rounded to 4 sig figs = 4.780

3.995 divided by .500

3.995 has 4 sig figs

.500 has 3 sig figs

answer will have 3 sig figs

Answer: 7.99

10 has 1 sig fig

10. has 2 sig figs

10.0 has 3 sig figs

.1 has 1 sig fig

.10 has 2 sig figs

.1000000 has 7 sig figs

Placement of the decimal point and zeros plays a big roll in determining the number of significant figures.

10 without a decimal point only has 1 sig fig, the zero is simply a place holder.

Adding the decimal point makes the zero have meaning. It means the accuracy is know to the ones column.

Here are some good online lessons:

Scientific Notation:

http://www.nyu.edu/pages/mathmol/textbook/scinot.h...

Significant Figures:

http://www.chem.sc.edu/faculty/morgan/resources/si...