Using the calculator

READY0

The top line of the display shows READY, or the pending operation, like 12 ×. The bottom line shows the number you are typing or the latest result.

Keys

Key	What it does	Keyboard
0–9	Types a digit. Numbers can be up to 15 digits long.	0–9
.	Adds a decimal point. Starts a new number as 0.	. or ,
+ − × ÷	Chooses the operation. Pressing another one right after replaces it.	+ - * or x /
=	Shows the result.	Enter or =
%	Divides the shown number by 100.	%
±	Flips the sign of the shown number.
DEL	Deletes the last digit you typed.	Backspace
C	Clears everything.	Delete or C
♪	Mutes or unmutes the keypad. See Muting.

How it calculates

It works like a basic pocket calculator, one step at a time from left to right. There is no operator precedence: 2 + 3 × 4 = gives 20, not 14.

• Chained operations. Pressing an operator after a second number works out the result so far: 2 + 3 × shows 5, then waits for the next number.
• Repeat equals. Pressing = again repeats the last operation: 5 + 2 = = = gives 7, 9, 11.
• Reuse the number. Pressing = straight after an operator uses the shown number twice: 6 × = gives 36.

How results are shown

• Trailing zeros are dropped, so 0.5 × 4 = shows 2.
• Results longer than 16 characters switch to scientific notation, like 1.23456789e20.
• Values closer to zero than 0.000000000001 show as 0.

Errors

Dividing by zero, or a result too large to store, shows Error. Typing a digit or . starts a fresh calculation, and DEL or C clears it. Other keys do nothing until then.