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MATHEMATICS IN SCIENCE
Objectives
1. To give concrete examples on how mathematics play an important role in our everyday life
2. To solve problems involving the SI unit of measurement and Scientific Notations
3. To become familiar with the different tools used for measurement
• SI =Systeme International d’Unites. • based on the metric system of measurement
that was developed by France. • ideal because it is a decimal system. • Simple relations exist between units and
equivalents and they are expressed in multiples of 10.
• SI is consist of a set of units together with a set of prefixes.
SEVEN SI BASE UNITSQuantity Name Symbol
Mass kilogram kgTime second s
Length meter mElectrical current ampere A
Temperature kelvin KAmount of substance mole molLuminous intensity candela cd
TABLE OF PREFIXES USED IN SI UNITS
Prefix Abbreviation
Exponential expression
Decimal Expression
Mega M 106 1,000,000Kilo K 103 1,000
Hekto H 102 100Deka da 101 10Deci d 10-1 0.1Centi c 10-2 0.01Milli m 10-3 0.001
Micro μ 10-6 0.000001nano n 10-9 0.000000001
English system1 in = 2.54 cm 1 ft = 0.3 m1 yrd = 0.91 m1 mi = 1.61 km1 ml = 1cm3
1 liq quart = 0.95 L1 dry quart = 1.10 L1 gal = 3.80 L
1oz = 28.35 g1lbs = 0.45 kg
Conversion of units
• Conversion Factor must always be equal to 1• how many meters can be found in 5
kilometers?
5km x 103m = 5000m 1 1km
Significant FiguresTo avoid ambiguity in the number of significant figures, such number should be written in exponential notation
730 (3 significant figures) – 7.30X102
760 (2 significant figures) – 7.6X102
16,000 (3 significant figures) – 1.60x104
ROUNDING OFF RULES1. When the number dropped is less than 5, the preceding number remains unchanged. Thus, 1.874 rounded off to 1.87 and 0.056452 is rounded off to 0.05645.
2. When the number dropped is more than 5, 1 is added to the preceding number. Thus, 4.7438 is rounded off to 4.744 and 0.0526 is rounded off to 0.053.
3. When the number dropped is exactly 5, if the preceding number is even, it remains unchanged; if the preceding number is odd, 1 is added to it. Thus, 7.245 is rounded off to 7.24 and 13.7735 is rounded off to 13.774.
Rounding off for Addition and Subtraction
• The answers should be rounded off so as to contain the same number of decimal places as in the number with the least decimal places.
Rounding off for Multiplication and Division
• The answer should be rounded off as to contain only as many as significant figures as in the number with the least number of significant figures.