(CDT) BigDecimal provides arbitrary-precision floating point decimal arithmetic
Ruby provides built-in support for arbitrary precision integer arithmetic. For example: 42**13 -> 1265437718438866624512 BigDecimal provides similar support for very large or very accurate floating point numbers. Decimal arithmetic is also useful for general calculation, because it provides the correct answers people expect–whereas normal binary floating point arithmetic often introduces subtle errors because of the conversion between base 10 and base 2.
