Saile --

I'd seen this before.

The keyboard is useful only as an enhanced version of a regular keyboard -- complete with decimal point *and base-ten exponent*. Keystrokes are saved only if the number contains multiple zeroes -- in particular, significant zeroes between non-zero digits. Otherwise, it's just as quick (or quicker) to enter numbers in the usual manner using "E".

For scientific calculators, the four positions needed for the unshifted 'hundreds', 'thousands', 'millions', and 'billions' keys are just too valuable to employ in this manner.

For applications in science and engineering, numbers with many digits are generally not entered from the keypad -- those would imply more significant digits than are justified. One exception to that, pi, invariably has a dedicated key for entry.

For many years, cash registers and calculators for accounting have had special keys for "00" and "000".

-- KS

*Edited: 22 Feb 2009, 3:15 p.m. *