120 likes | 370 Views
Significant Digits. Uncertainty of Measurement. Three Rules. Non-zero digits are significant Zeros between two significant digits are significant Zeros at the right end of a number, after a decimal point, are significant. Number 455.6 7.98 0.6224 5.2.
E N D
Significant Digits Uncertainty of Measurement
Three Rules • Non-zero digits are significant • Zeros between two significant digits are significant • Zeros at the right end of a number, after a decimal point, are significant
Number 455.6 7.98 0.6224 5.2 Significant Digits 4 3 4 2 Non-zero digits are significant
Zero to left of decimal point • 0.78895 5 significant digits • The zero to the left of the decimal point is there to communicate that the decimal point is a decimal point - convention
Problems! • Numbers like 308.5 0.000811 5000
Number 28.09 1008.91 3.005 2.03 Significant Digits 4 6 4 3 Zeros between non-zero digits are significant
Space Holding zeros on numbers less than one • 0.00678 3 significant digits • 0.030086 5 significant digits
Trailing Zeros • 200 is considered to have only one significant digit • 38,000 has two significant digits
Problem area • 5000 might really have four significant digits - an exact count or measurement • write number as 5000. • Scientific notation used to indicate significant digits
78002.1 0.00006003 34.61 8.81 42,300 6 4 4 3 3 Review
Multiplication & Division • An answer cannot have more significant digits than the measurement with the least number of significant digits used in the operation. (3.006) X (0.0067) = 0.0201402 = 0.020 only 2 sig. Digits
Addition & Subtraction • The answer is rounded to the least number of places in the decimal portion of any number in the operation 134.008 89.70 57.9 281.608 = 281.6