Angles: Degrees, Radians and Gradians Converted
Why three angle units survive, the conversion bridge, and the five-second sin(30) test that diagnoses the most expensive calculator mistake.
The factors, the shortcuts and the classic traps of converting length, weight, temperature, volume, speed, pressure, data and angles. Each guide lists the mental-math trick together with its error, so you know when an estimate is good enough.
Why three angle units survive, the conversion bridge, and the five-second sin(30) test that diagnoses the most expensive calculator mistake.
Tires, weather maps, blood pressure and scuba all measure the same thing in different units; two memorized factors connect the whole family.
The most booby-trapped unit family: two gallons, three cups, the pint that changes size mid-Atlantic, and the fuel economy inversion.
The two-step formula, anchor points worth memorizing, a mental trick with zero error, and the oven, fever, and weather conversions people actually need.
The two unit ladders, where the missing gigabytes go, why 100 Mbps is 12.5 MB/s, and the size reference table for sanity-checking storage.
Two shortcuts that are secretly a matched pair, the speed limit tables drivers actually meet, the runner’s pace inversion, and the knot.
One principle, a handful of exact factors, five traps (two gallons, GB vs GiB, three tons), and links to every converter and dedicated guide.
The exact factor, the base-12 step where height conversions go wrong, a full height table, and shortcuts with their honest error attached.
Multiply by 2.2 and lose only 0.21%: the shortcuts, the luggage trap that costs real money, and the units around the pound worth knowing.