Unit Prefixes
A ladder of powers of ten from tera down to pico: click any rung and the same physical quantity re-expresses itself in that prefix, showing exactly how many places the decimal point moved and by what factor. Six real quantities — LED current in milliamps, red light in nanometres, turbine output in megawatts — each with a note on why the conversion actually matters in a calculation. Every value on the ladder was verified in code to reconstruct the exact original quantity, and all 121 prefix-to-prefix conversions verified to round-trip. A drill section then tests conversion both directions, where every wrong option is a real student mistake: converting the wrong way, missing by a factor of a thousand, or forgetting to convert at all.
Meters read in milliamps; the formula I = V/R wants amps. This conversion is the single most common slip in circuit questions.
Every physics formula wants base units. Convert first, then calculate — never the other way round.
1. Click from milli straight to kilo. The decimal jumps six places at once — a prefix change is never one step unless the rungs are adjacent.
2. Notice centi is only 10⁻², not 10⁻³. It breaks the three-at-a-time pattern, which is why cm → m trips people up.
3. In the drill, look at the wrong answers before choosing — each one is a real mistake: converting the wrong way, missing by a thousand, or not converting at all.