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The following numbers have 1 significant figure: 3 40 0.1 0.0002 5 x 10 6. The following numbers have 2 significant figures: 0.00016 1.0 37 450 2.5 x 10 -2. The following numbers have 3 significant figures: 42.9 0.000116 870. 725 5.10.
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The following numbers have 1 significant figure:3 40 0.1 0.0002 5 x 106
The following numbers have 2 significant figures: 0.00016 1.0 37 450 2.5 x 10-2
The following numbers have 3 significant figures: 42.9 0.000116 870. 725 5.10
The following numbers have 4 significant figures: 870.0 0.0001100 3125 2500.
Write some “rules” for how to determine which digits are significant and which digits aren’t significant. - Any non-zero digit is significant. - Zeroes to the left of a decimal that is shown are significant. (e. g. 2500.0 All these zeroes are significant) - Leading zeroes are not significant, i. e., any zero to the left of a non-zero digit is not significant. (e. g. 0.00001 all these zeroes are to the left of the first non-zero digit, so they are not significant) - -
Rules continued… • Zeroes to the left of an “invisible” decimal are not • Significant--they are called “trailing zeroes”. (e. g. 870 • There is no decimal shown, so the zero is not significant.) • Zeroes to the right of a shown decimal are significant if they • also occur to the right of a non-zero digit. (e. g. 70.0 The • Right-most zero is significant because it occurs to the right • Of a non-zero digit and the decimal is shown
Rules Continued… • When adding or subtracting 2 numbers, the number with the least number of decimal places determines the amount of decimal places in the answer. • E. g. 3.01 - 2.0 = 1.0 The fewest number of decimal places was “1”, so there is only 1 decimal place in the answer
Rules, Continued • When multiplying and dividing, the number with the fewest significant figures determines how many significant figures are in the answer. • E. g. 0.25 x 4000. = 1.0 x 103
Create 2 numbers that have: • 1 sig fig: _4___, _0.01___ • 2 sig figs: _0.021___, _0.35__, 250__ • 3 sig figs: _267___, __300.__ • 10 sig figs: __0.1 000 000 000___, _70.00000001_____
How many signficant figures do the following numbers have? 1.23400 1,234,000 0.00012 1.20 x 10-2 5000 0.000009