Order of Magnitude
Summary
- A number in scientific notation has the form…
a × 10n
where…a is a decimal number called the mantissa n is an integer called the order, index, exponent, or power - Scientific notation is a method for writing numbers that…
- is useful for writing numbers that are too large or too small to write conveniently in decimal form
- simplifies some mental calculations
- There are two conventions for writing numbers in scientific notation.
standard form
0 < a < 10
- The mantissa has a single non-zero digit before the decimal point.
- Significant digits are isolated from the placeholder digits
engineering notationn = 0, ±3, ±6, ±9, …
- The order is an integer multiple of 3.
- Determining SI prefixes is made easier.
- Order of magnitude
- An order of magnitude change is an increase or decrease by a power of 10.
- Estimation should lead to values that are within an order of magnitude of their actual value.