Scientific and Engineering Notation

Electronics constantly uses very large and very small numbers — a resistor might be 4,700,000,000 ohms and a capacitor 0.000000000001 farads. Scientific notation writes these as a coefficient times a power of ten, where the coefficient is at least 1 and less than 10. To convert, move the decimal point until one digit remains to its left, count the places moved, and make the exponent positive if you moved left or negative if you moved right: 4,700,000 becomes 4.7 × 10⁶ and 0.0056 becomes 5.6 × 10⁻³.

Engineering notation is scientific notation whose exponent is always a multiple of 3 — because each SI prefix step is a factor of a thousand. That lets you swap the power of ten for a prefix: 4,700 ohms is 4.7 × 10³ ohms, which is simply 4.7 kΩ, and 8.2 × 10⁶ Hz is 8.2 MHz. To convert between prefixes, move the decimal three places per prefix step: 0.047 A is 47 mA, and 0.047 µF is 47,000 pF.