What is the repeating sign on a calculator?

Answer 1

If you mean for a repeating decimal, then most (old) calculators used to not have it and just round the answer. However, more modern calculators with "natural math display" use the correct mathematical method of putting a dot over a single repeating digit (eg 1/6 = 0.1666... would be displayed as 0.16 with a dot over the 6), or a dot over the first and a dot over the last repeating digits if there are more then one (eg 1/7 = 0.142857... and would be displayed with a dot over the 1 and another over the 7).

If you mean for repeating an operation (eg 5 + 2 + 2 + 2...) then this repetition is either displayed by a letter k or the operation sign being constantly displayed on the screen. To achieve this some calculators require the operation to be pressed twice whereas others do it automatically. Modern "natural math display" calculators do not have this function; instead they tend to have a last entry recall feature (to allow for editing) and so the same result would be achieved by re-entering the operation (eg + 2 which would display as ANS + 2) and then using the equals and recall buttons in turn to repeat the operation.

Answer 2

Normal calculators do not have a repeating sign.