By working backwards, <span>you get 76 as your answer because you have to remove the rightmost digit, right? so the three-digit number is </span>
<span>76x </span> <span>(x stands for the rightmost digit, because we don't know what the rightmost digit is) </span>
<span>we are told we have to add six to the three digit number to get 76x, so we have to subtract 6 from 76x: </span> <span>76x - 6 = ??? </span>
<span>since we assume that the original two-digit number is NOT 76, and any number from 760 to 765 inclusive minus 6 is logically in the 750-range, we can conclude that the original two-digit number is 75. </span>