WHAT DOES AC MEAN ON A CALCULATOR?
calculators have several keys with functions that clear different things, so users are often unsure which key does what. Let's try to clear up the confusion.
AC stands for All Clear and, as the name suggests, it clears everything - display (screen),
entry registers and memory. You can consider this a full reset of the calculator where all values are set to zero.
C stands for Clear and clears the display and entry registers but won't clear any data in
memory. For example, lets say you calculate "3 x 15". You'll see the result of "45" on the display. If your calculator has a memory function, you can store
this value "45" in memory. If you then press the C key, you'll clear the display to zero but leave 45 in the memory. You can still
recall it to use in another calculation.
MC stands for Memory Clear and clears the memory but not the display. Using the previous
example, if you have the value of "45" in both display and memory, pressing the MC key will leave it on the display but clear the
memory to zero.
CE stands for Clear Entry and clears the last entry. For example, let's say you want to
calculate "3 x 15" but type "16" as the second value instead of "15". You can press CE to clear the second value of "16" then
enter "15" instead. The first value of "3" remains in the entry register, so when you press the = key, you'll get the correct result
Just to make things more complicated, there is often a Backspace or Del key which clears the last character
only, not the full entry. For example, if you type "16" but meant to type "15", you can press Backspace to erase the "6" then enter
Remember, not every calculator has every key. Also, some calculators use different keys for the same function or combine keys. For example, it is
quite common to see the CE and C keys combined into one CE/C key. The first press
clears the last entry and the second press clears all.
More advanced calculators have a lot of memory and functions, so there's more to clear. This can lead to more keystrokes to clear the calculator. For
example, many financial calculators use the key combination f CLx to
More complicated again, you'll need to press 6 keys to clear RAM memory and display on a TI-84 Plus calculator. The key combination is
2nd + 7 1 2 clear. If you want to clear everything including programs, apps, archived programs
and variables, you'll need to clear RAM and Archive memory using the key combination
2nd + 7 -> -> 1 2 clear.
Want more information about calculator keys? Check out our guide to calculator keys and functions.