Order of operations
2 + 3 × 4 = 14
The top line keeps the whole sum. Equals does the multiplication first. There are no bracket keys, so write the sum in an order that does not need them, or break it into two lines on the tape.
Free online calculator
A desk calculator in the browser: keyboard or keys, a paper tape for this visit, and multiplication before addition. Updated 6 October 2026.
M
0
How the keys behave
Percent
200 + 10% = 220
200 × 10% = 20
After plus or minus, percent means “this percent of the number just before the operator.” After multiply or divide, it divides the number you just typed by 100. On its own, 50% becomes 0.5.
Scientific
sin(90°) = 1
Sine, cosine, and tangent use degrees, not radians. They apply to the number on the display, then the result can continue in a longer sum. Square root of a negative number, and tangent of 90 degrees, show Error.
Common questions
Can I use the keyboard?
Yes, when you are not typing in another field. Digits, decimal point, plus, minus, star, slash, percent, Enter, Backspace, and Escape all work. Escape clears.
Is the history saved?
No. The tape lasts for this page view. Reload and it is gone. Nothing is uploaded.
What does the memory row do?
M+ adds the displayed number to memory, M− subtracts it, MR recalls it, and MC clears memory. An M on the display means memory is not zero.