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Significant Figures. Significant figures tell you about the ________________________in a measurement . Significant figures include all ________________ _______________________________________. 11.84 cm. Significant Figures.
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Significant Figures • Significant figures tell you about the ________________________in a measurement. • Significant figures include all ________________ _______________________________________ 11.84 cm
Significant Figures • Significant figures include all CERTAIN (known) digits, and ONE UNCERTAIN (guessed) digit 520 cm
How many Sig. Figs.? Two rules: • #1) If there IS a decimal point in the number: • __________________________________________ __________________________________________
How many Sig. Figs.? 2 3 . 0 0 2 8 0 1 0 0 . 0 6 8 0 0 1 0 0 . 0 0 0
How many Sig. Figs.? Two rules: • #1) If there IS a decimal point in the number: • Start at right of number and count until the LAST non-zero digit • #2) If there is NOT a decimal point in the number • __________________________________________ __________________________________________
How many Sig. Figs.? 7 4 2 9 3 2 3 0 8 0 0 1 0 0 0 0 0
Significant Practice 320000 8900. 0.0061000 0.1528 60020300 12.00500 0.0005 0.10046
Rounding Numbers • Find the last significant digit. • If the next digit to the right is 4 or less, leave the last significant digit alone. • If the next digit to the right is 5 or more, round the last significant digit up.
0.00259428 (3 s.f.) 54.3675701 (5 s.f.) 8265391000 (2 s.f.) 0.1659822 (4 s.f.) 0.0005473300 (5 s.f.) 2617890100 (6 s.f.)
Calculations with Sig. Figs. • Multiplication and division • _______________________________________ _______________________________________ _______________________________________ 1.5 x 7.3254 = 1 0 .9881 6.127 x 0.0000267030 = 0.000163 6 09
Calculations with Sig. Figs. 927.381 / 456.0 0.00159 / 2
Some Practice 500 x 0.000230012 890.00 x 112.3 78132/2.50 0.0120 x 48.15 x 0.0087
Sig. Figs. in Calculations Two rules: • #1) Multiplication and Division: • The value in the calculation that has the FEWEST number of sig. figs. determines the number of sig. figs. in your answer. • #2) Addition and Subtraction: • _________________________________________ _________________________________________ _________________________________________
Adding and subtracting with sig. figs. 0.0025647 + 0.000321
Adding and subtracting with sig. figs. 394.0150 + 0.0074121
Adding and subtracting with sig. figs. 682300 + 5922.60
Some More Practice 23.67 – 75 5502.8 + 24.691 + 0.01 0.109 + 0.09 – 0.955 20.4 + 1.322 + 78 0.000004 + 11.23115 5449000 + 162211
Scientific Notation – Numbers > 1 Place a decimal so that there is a single digit to the left 18900000 Start counting from the right until you get to the decimal This becomes the exponent for “times 10 to the” Remove digits from the right until proper # of sig. figs.
Scientific Notation – Numbers < 1 Start counting from the decimal point to the first non-zero digit. This will be the exponent in the “times ten to the negative” 0. 0 0 0 0 0 0 5 7022169 Move the decimal point to the right of the first non-zero digit, drop all of the leading zeros, and add the “times ten to the negative” with the exponent.
Did you get it? • 512384000 4 s.f. • 0.0006000 2 s.f. • 0.00251634 5 s.f. • 3540000000 5 s.f.
Percents percent percent percent _________________________________________________ _________________________________________________
Percents ______ of the mass of __________ is made up by _________ ____________________________, ____________________________
Percents _____________ account for __________ of _______ ____________ are PART OF ______, ______ are NOT part of __________
Percents 0.0060% of the mass of the human body is made up by iron
Percents In Spring 2012, 16319 of the 31751 registered students at ARC were female.
Percents In 2000, golden retrievers accounted for 66300 of the 1175473 dogs registered in the United States.