Keypad Mode is a mouse-based interface to the Calculator. It is designed for use with the X window system. If you don't have X, you will have to operate keypad mode with your arrow keys (which is probably more trouble than it's worth).
Type M-# k to turn Keypad Mode on or off. Once again you get two new windows, this time on the righthand side of the screen instead of at the bottom. The upper window is the familiar Calc Stack; the lower window is a picture of a typical calculator keypad.
|--- Emacs Calculator Mode ---
|2: 17.3
|1: -5
| .
|--%%-Calc: 12 Deg (Calcul
|----+-----Calc 2.00-----+----1
|FLR |CEIL|RND |TRNC|CLN2|FLT |
|----+----+----+----+----+----|
| LN |EXP | |ABS |IDIV|MOD |
|----+----+----+----+----+----|
|SIN |COS |TAN |SQRT|y^x |1/x |
|----+----+----+----+----+----|
| ENTER |+/- |EEX |UNDO| <- |
|-----+---+-+--+--+-+---++----|
| INV | 7 | 8 | 9 | / |
|-----+-----+-----+-----+-----|
| HYP | 4 | 5 | 6 | * |
|-----+-----+-----+-----+-----|
|EXEC | 1 | 2 | 3 | - |
|-----+-----+-----+-----+-----|
| OFF | 0 | . | PI | + |
|-----+-----+-----+-----+-----+
@begingroup @ifdim@hsize=5in @advance@hsize-2.2in @else @advance@hsize-3.05in @advance@vsize.1in @fi
Keypad Mode is much easier for beginners to learn, because there is no need to memorize lots of obscure key sequences. But not all commands in regular Calc are available on the Keypad. You can always switch the cursor into the Calc stack window to use standard Calc commands if you need. Serious Calc users, though, often find they prefer the standard interface over Keypad Mode.
To operate the Calculator, just click on the "buttons" of the keypad using your left mouse button. To enter the two numbers shown here you would click 1 7 . 3 ENTER 5 +/- ENTER; to add them together you would then click + (to get 12.3 on the stack).
If you click the right mouse button, the top three rows of the keypad change to show other sets of commands, such as advanced math functions, vector operations, and operations on binary numbers.
@endgroup Because Keypad Mode doesn't use the regular keyboard, Calc leaves the cursor in your original editing buffer. You can type in this buffer in the usual way while also clicking on the Calculator keypad. One advantage of Keypad Mode is that you don't need an explicit command to switch between editing and calculating.
If you press M-# b first, you get a full-screen Keypad Mode
(full-calc-keypad) with three windows: The keypad in the lower
left, the stack in the lower right, and the trail on top.
See section "Keypad" Mode, for further information.