Transcript Significant Figures - Solon City Schools

Significant Figures
Used to report all precisely known
numbers + one estimated digit
Rule #1

Every nonzero digit is significant
Examples:
24 = 2
3.56 = 3
7
=1
Rule #2

Zeros between non-zeros are significant
Examples:
7003 = 4
40.9 = 3
Rule #3

Zeros appearing in front of non-zero digits
are not significant
 Act
as placeholders
 Can’t be dropped, show magnitude
Examples:
0.00024 = 2
0.453
=3
Rule #4

Zeros at the end of a number and to the
right of a decimal point are significant.
Examples:
43.00 = 4
1.010 = 4
1.50 = 3
Rule #5

Zeros at the end of a number when no
decimal point is present aren’t significant.
Examples:
300
=1
27,300 = 3
Special Rule

Always remember PA
P
A
If a decimal point is present, start on the Pacific (P) side and begin
counting at the first non-zero digit all the way to the end.
If a decimal is absent, start on the Atlantic (A) side and begin counting
at the first non-zero digit all the way to the end.
Special Rule (cont.)

Remember PA
Examples:
123.003 = decimal present, start
on “P” side, begin counting
Answer = 6
Special Rule (cont.)

Remember PA
Examples:
204,000 = decimal absent, start
on “A” side, begin counting at first nonzero digit until you hit the end of the
number.
Answer = 3
Sig. Fig. Math Rules

Multiplication / Division:
Your answer can’t have more sig. figs.
than the number in the problem with the
least amt. of sig. figs.
Example = 60.56227892 x 35.25
Calculator says – 2134.890832 (wrong)
Answer - 2135
Sig. Fig. Math Rules
Addition / Subtraction:
Answers can’t have more numbers to
the right of the decimal point than the
number in the problem with the least amt.
of numbers to the right of the decimal
point.
Example = 24.1 + 3.35 + 2.23
Calculator says – 29.68 (wrong)
Answer – 29.7
