1. Scientific Notation and Metric Prefixes
February 6, 2012

2. Scientific Notation
When working in electronics it is common to encounter very small and very large numbers.
Scientific Notation is a means of using single-digit numbers plus powers of ten to express very large and very small numbers. i.e. 3x103 = 3000

3. Scientific Notation cont.
The exponent indicates the number of decimal places to the right or left of the decimal point in the number. If the power is positive the decimal point moves right if negative it moves left. i.e.
3x107 = = 30,000,000 or
2.7x10-3 = =

4. Metric Prefixes
Because the fundamental units are not always a convenient size prefixes are used to change the size of the units. The prefix multipliers change the value of the unit by powers of ten.
Unless asked for a specific unit, it is more convenient to use a unit that is similar in size to the quantity you are measuring.
For example, it is much more convenient to specify the diameter of a contact lens as 1.0 cm than as 1.0 X 10-2 m.

5. Metric Prefixes Prefix Symbol Value Decimal Value Giga- G 109
1,000,000,000
Mega- M
106
1,000,000
Kilo- k
103
1,000
Milli- m
10-3
0.001
Micro-
10-6

6. Using Metric Prefixes
When recording readings or answering mathematical problems use metric prefixes if the numbers are too big or small for the standard unit. i.e.
Reading Current in Amps:
A = 2.34x10-3A = 2.34mA
Reading Resistance in Ohms(Ω)
23,000,000Ω = 2.3x107Ω = 23MΩ

7. Now… See me for Scientific Notation and Metric Prefix assignment
It is to be done individually
Is worth 20 marks