Unit #1Unit #2Unit #3Unit #4Unit #5Unit #6Unit #7Unit #8Unit #9Unit #10
spacerUNIT # 1  
spacerspacerIntroduction
spacerspacerObjectives
spacerspacerReading

spacer1.1
Metric
spacerSystem
spacerSI System
spacerBritish System

spacer1.2 Temperature
spacerMeasure-
spacerments

spacer1.3 Scientific
spacerNotation

spacer1.4 Dimensional
spacerAnalysis

spacer1.5 Precision,
spacerAccuracy,
spacerUncertainty

spacerLimitation of the Measuring Instrument
spacerAnalysis of the Limitation of a Ruler
spacerAnalysis of the Limitation of another Ruler
spacer1.6 Significant
spacerFigures

spacerThe Magnitude and Reliability of the Measurement
spacerFive Rules for Determining the number of Significant Figures in a Measurement

spacer1.7 Calculations
spacerInvolving
spacerSignificant
spacerFigures
spacerRules for Rounding off Numbers
spacerRules for Addition  and Subtraction

spacerRules for Multiplication and Division

spacer1.8 Density
spacerDensity and Temperature
spacer1.9 Specific
spacerGravity
spacerspacerProblems
spacer1 | 2 | 3
   

MEASUREMENT

1.7 - Calculations Involving Significant Figures

Now that you've learned the importance of recording measurements to the proper number of significant figures, it is very likely that you will be doing calculations with these measurements. The type of calculations that you will most likely carry out are the following types of mathematical operations:

  1. addition
  2. subtraction
  3. multiplication
  4. division

It is important to know how to determine the proper number of significant figures in your answer AFTER you have completed mathematical manipulations of the measurements.

For example,

let's say you have taken the following measurements for calculating the area of a table-top.

width = 50.996 cm
length = 75.4 cm

To calculate the area of the table-top, the area would equal 50.996 cm x 75.4 cm. The calculator answer is

When you record the area of the table-top, should you record

area = 3845.0984 cm2
(No!)


The calculator displays too many figures. You need to know some rules in determining the proper number of significant figures of an answer which resulted from a mathematical operation. Read on ... (the answer to this example is in section 1.7.3).

Section 2.6
Mathematical Operations Involving Significant Digits ..p23

 

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