Transcript significant-figures

Significant Figures
& Scientific Notation
Rules for SigFigs
1. Any non-zero digit is significant
2. Any trapped zeros are significant
3. Zeros to the left of the decimal point at the
end of a number are NOT significant
(trailing zeros)
4. Zeros to the right of the decimal point at
the beginning of a number are NOT
significant (leading zeros)
5. Answer can have only as many sigfigs as
the fewest in the problem
EXAMPLES
• 23 – both are non-zero numbers (2 sigfigs)
• 109 – zero between two non-zero numbers
(trapped zero – 3 sigfigs)
• 4500 – trailing zeros before the decimal are
NOT significant (2 sigfigs)
• 0.000785 – leading zeros after the decimal
are NOT significant (3 sigfigs)
• 6.00 – trailing zeros after the decimal ARE
significant (3 sigfigs)
Scientific Notation
1. Can be only 1 number to the left of the
decimal
2. Second part is written as (x 10n)
3. If the number to be written is smaller than 1
then n MUST be negative
4. If the number to be written is larger than 1
then n MUST be positive
EXAMPLES
Write the following in scientific notation:
157 – move decimal two places to left
1.57 x 102
23000 – move decimal four places to left
2.3 x 104
0.0000279 – move decimal five places to right
2.79 x 10-5
0.000000000324 – move decimal ten places to right
3.24 x 10-10