Significant figures

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Def: Tell us how to round and to make sure the answers you get isn't more precise than the numbers you started with.

1-4= 0

5-9= you add 1 to the number on the left

you have to count the significant figures to know where to round.

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excercise

25,300,000,000,000. miles

2.53 x 10 to the 13

0.000 000 0203 seconds

2.03 x 10 to the -8

you move the decimal point to the left it will be a positive exponent and if you move it to the right it will be a negative exponent.

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1. All non-zero numbers ARE significant.

example: 35

2. Zeros between two non-zero digits ARE significant.

example: 3506

3. Leading zeros are NOT significant.

example: 0.0035

4. Trailing zeros to the right of the decimal ARE significant.

example: 35.00

5. Trailing zeros in a whole number with the decimal shown ARE significant.

example: 350.

6. Trailing zeros in a whole number with no decimal shown are NOT significant.

example: 350

7. For a number in scientific notation: N x 10x, all digits comprising N ARE significant by the first 6 rules; "10" and "x" are NOT significant.

example: 5.02 x 104 has THREE significant figures: "5.02." "10 and "4" are not significant.

examples:

0053205000000 = 5 significant figures

005320.5000000 = 11 significant figures

0.053205000000 = 11 significant figures

5.3 x 10 to the 2 = 2 significant figures

5.30 x 10 to the 2 = 3 significant figures

0.0530 x 10 to the 2 = 3 significant figures

0.0530 x 10 to the -6 = 3 significant figures

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