Do ‘hand-held’ calculators use decimal arithmetic?
Yes. The first microprocessor-based electronic calculator, the Busicom (actually a desk-top machine), used its Intel 4004 to implement decimal arithmetic in 1970. Later, the Hewlett Packard HP-71B calculator used a 12-digit internal decimal floating-point format (expanded to 15 digits for intermediate calculations), to implement the IEEE 854 standard. Today, the Texas Instruments TI-89 and similar calculators use a 14-digit or 16-digit Binary Coded Decimal internal floating-point format with a three digit exponent. HP calculators continue to use a 12-digit decimal format; Casio calculators have a 15-digit decimal internal format. These all use software to implement the arithmetic, as single-calculation performance is not usually an issue. Oddly, most calculators discard trailing fractional zeros.
