HP 20 b 15-digit Precision

The HP 20 B calculator performs all calculations internally with 15-digit precision and rounds to 12 digits when returning the results. When displayed, a number is rounded to the number of digits after the decimal point set by the FIX= item in the Mode menu. The default setting is two digits to the right of the decimal point. The FIX= setting only affects the display; it does not affect the actual numbers.