You don't have to use long division to work this out: you can use continuous subtraction: 112-30=82 (first subtraction); 82-30=52 (second subtraction); 52-30=22 (third subtraction). 22 is smaller than 30 so we can't subtract any further. So since we carried out three subtractions the answer is 3 (and the remainder is 22).

Another way is to spot that 3 times 10 is 30, and dividing by 10 means losing or decimalising the units. So 112 just becomes 11 for the purposes of this problem and 3 goes into 11 3 times and a bit over (it's 2 over, and if we join it up with the units we threw away we get 22, which is the actual remainder).