How to 29

Many people, despite their best efforts, still cannot come up with a satisfactory answer to this mathematical puzzle. Specifically, the puzzle is as follows: "How to correctly perform the calculation 29 - 1 = 30?".

Surely this problem will make 99% of readers give up because they cannot find the correct answer. Please be patient, think and calculate carefully about many possible cases so that the calculation 29 - 1 = 30 is correct.

If you can answer this math puzzle correctly, you must be a math genius with a world- class IQ.

Scroll down to the comments section to write your answer to see how 29 - 1 = 30.