Transcript Significant Figures

Significant
Figures
The Basics
 All


nonzero digits are significant
Ex: 1.2 – 2 significant digits
Ex: 1.2341 has 5 significant digits
 Zeroes
between nonzero digits are
significant


Ex: 1008 has 4 significant digits
Ex: 5.007 has 4 significant digits
The Basics

Leading zeros to the left of the first nonzero
digits are not significant; such zeroes merely
indicate the position of the decimal point



Ex: 0.0001 has 1 significant digit
Ex: 0.0012 has 2 significant digit
Trailing zeroes that are also to the right of a
decimal point in a number are significant

Ex: 0.020 has 2 significant digit
The Basics
 When
a number ends in zeroes that are
not to the right of a decimal point, the
zeroes are not necessarily significant

Ex: 290 may have 2 or 3 significant digits.
 Exception
to this rule is the use of scientific
notation. All digits in the first part of a
scientific notated number are significant.

Ex: 5.0020 x 106 has 5 significant digits
Exact Numbers
 Some
numbers are known to be exact.
These are often used as conversion
factors as discussed yesterday.


There are exactly 12 inches in 1 foot.
There is exactly 100 cm in 1 meter.
Math Rules
 When
performing a math problem, the
number in the problem with the least
amount of significant digits determines
the answer.

Ex: 5.86 x 21.5482 = 126.272452. This should
be rounded to 3 significant digits, 126.