To define a non-default format of results, after the appropriate results symbol, type:
General and scientific formats are identical for numbers ≥107 and ≥10-7. Otherwise, the general format is similar to the fixed format, except that any trailing zeros after the decimal point are removed.
The engineering format gives a number between 1 and 999 × 10?, where ? is a multiple of 3 (3, 6, 9, -3 and so on).