Number to Words

Three decimal modes cover almost every real-world need. Cheque mode is the format banks and lawyers expect: 12.56 → "twelve and 56/100". Point mode is everyday speech — "twelve point five six". Locale only changes whether and is inserted (US omits it, UK inserts it between groups when the lowest is below one hundred). Negative numbers always read outside the currency label ("negative twelve dollars and 34/100"). The integer part uses BigInt so every value up to 999 decillion round-trips exactly; inputs above that fall back to a friendly cap instead of silently truncating.