Percent just means what part of 100 omething is.
So your 23% is 23 out of 100 or as a fraction this would be 23/100. if you go ahead and do this division (i.e. 23 divided by 100) you will get 0.23 which is the decimal form for the fraction.
In fact any fraction can be converted to a decimal form by just going ahead and doing the division.