On many graphics calculators, there are keys which allow you to recall and change or ‘edit’ what you have entered. Suppose in tackling one of the above calculations you entered the following, by mistake:
4 5 7 9 3
Pressing will give the answer 16, which is not what you were expecting. Then you spot the mistake, which was that 5 was entered instead of 2. Check your calculator to see if you can recall your entry and edit it. On the TI-84, you can press 2nd [ENTRY], which is the second function of . The original entry appears followed by a flashing cursor, which you can move until it lies over the 5, where upon you can press 2 to overwrite the 5 and press and the calculator will show the correct answer, 4.