170 likes | 335 Views
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. How many Significant Figures are in the number 3994 g. 4 5 2 One million! 0. Rule #2.
E N D
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
How many Significant Figures are in the number 3994 g. • 4 • 5 • 2 • One million! • 0
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
How many sig figs in the number 0.00678 kg. • 5 • 6 • 3 • infinite
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 and to the left of a decimal point aren’t significant Examples: 300 = 1 27,300 = 3
How many sig figs is the following measurement 809 cm. • 1 • 2 • 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 non-zero digit until you hit the end of the number. Answer = 3
How many sig figs are in the measurement 5600 km • 1 • 2 • 3 • 4
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
Choose the answer with correct # of sig figs9.0 cm + 7.666 cm + 5.44 cm • 22.1 cm • 22 cm • 22.106 cm
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
Perform the following calculation 5.35 m x 0.4 m = • 2 m2 • 2.14 m2 • 2.1400 m2 • 2.140 m2