I didn't do many, but outside of the first couple, I didn't notice any that had attainable answers without computation. One example was adding one hundred 100

I didn't do many, but outside of the first couple, I didn't notice any that had attainable answers without computation. One example was adding one hundred 100 digit numbers and returning the first 10 digits of the sum. The forums were full of "only the first 11 digits matter", "no the first 12 digits matter because there are 100 different numbers and 10^2 is 100", etc. No one considered: 000...00x90 111...11x9 000...01x1