Presentation on theme: "What is so significant about Significant Figures? The number of significant figures expressed in a measurement or calculation implies how precisely the."— Presentation transcript:
What is so significant about Significant Figures? The number of significant figures expressed in a measurement or calculation implies how precisely the quantity has been measured or calculated.
Significant figure or not? All non-zero digits are significant All zeroes between significant digits are also significant Zeros at the beginning of a number are NOT significant All zeros at the end of a number and after the decimal are significant Zeros at the end of whole number may or may not be significant. We will always assume that they are as in 2800 (use of scientific notation eliminates any ambiguity. For example x 10³ has four, and 2.8 x 10³ has only two)
How many significant figures?
Try This! With your ruler and calculator determine the volume of your cube in cubic centimeters V rectangle = l x w x h
Could you really calculate the volume of your cube as cm³? By reporting your answer this way you tell me that you measure its volume to within 1/1000 th or.001 of a cubic centimeter, or about the volume of a grain of sand.
Making Measurements with proper precision The significant figures in any measurement are the digits that are known plus one digit that is estimated. How many significant figures should you have in your measurement of the cubes length? 3 cm? 2.5 cm? 2.53 cm ? cm?
Performing Calculations When multiplying or dividing quantities, round off the answer to leave as many significant figures as there are in the original quantity with the least number of significant figures When adding or subtracting quantities, round off the answer to leave the same number of decimal places as you have in the original quantity that has the least number of decimal places.
Perform the operations below and provide an answer with the correct number of significant figures 3.00m · 9.1m · 0.903m = 67.0m /.0045s = 65s s +.9s = 18.66m³ m³ m³ 802mg g kg =
Recalculate the volume of the cube using correct significant figures beginning with the measured length and then the correct number of significant figures for all calculations