Ever wondered why the calculator, on windows systems and the hand held one, has two keys for deleting entries? We will explain why!!

Source: Wikipedia

The two keys either the CE and C or DEL and AC (in the latest models) have quite different functions. Since both keys clear data, the difference is hardly perceptible. The C key can clear the screen completely and bring the cursor to the very left of the screen. However, if you need to delete only the recent entry, CE will do that for you. CE will delete the right most digit only.

Source: HighSchoolMathAndChess 

In some latest models, this pair of C and CE keys has been renamed to AC and DEL respectively to make their function clear. The AC stands for All Clear where as DEL is short for delete, and thus deletes only the recent entry.

Hopefully, this new information will help you in using you calculator more efficiently.