Well how about this... instead of saying its md5 at the beginning of the round i use something like This to right down the number and encrypt it in one of those several ways and then I show at the end of the round the number and the type of hash which was shown.

Also if i were to use md5 only i could add multibple zeros to a number so its more complex and say tht take away all the zeros that are part of a zero and get anwser. ex. 00400000000000000000004000 would represent 44 but i would encrypt 00400000000000000000004000 into a hash