from the opposite of greatest 2digit no. subtract the greatest 1 digit Share with your friends Share 2 Rita answered this is not like that opposite of greatest 2digit is shouldbe smallest 10-9 =1 3 View Full Answer Nuhman answered this The greatest 2 digit number is 99.Reverse it and it will still remain the same. Then subtract the greatest one digit number,which is 9,from 99. So 99-9=90 0