write a program must do number conversions manually with control structures, string manipulation and mathematics, not by utilizing built-in C# library commands or print formatting, or no credit will be given. (You can use Math.pow or math library functions, but not any C# library converters that convert the values directly)

Program uses 4 or more programmer defined methods besides Main() 

Program correctly converts binary to decimal 

Program correctly converts decimal to binary 

Program correctly converts octal to decimal 

Program correctly converts decimal to octal