Help!! how do you make two numbers with decimals into compatible numbers in order to divide them???

Are you talking about a problem like

234.56 ÷ 54.321 using long division

Your divisor (the last number should not have any decimals, so move the decimal to the end of it, counting how many places it was moved.
Move the decimal of the dividend the same number of places.

so 234.56 ÷ 54.321
= 234560 ÷ 54321