3 ms·
MCMLXVII + LXV = MCCCCCCCCCLXVII + LXV (canonicalize) = MCCCCCCCCCLXVIILXV (concatenate) = MCCCCCCCCCLLXXVVII (sort) = MCCCCCCCCCLLXXXII (
by jeffcoat 6y ago
MCMLXVII + LXV
= MCCCCCCCCCLXVII + LXV (canonicalize)
= MCCCCCCCCCLXVIILXV (concatenate)
= MCCCCCCCCCLLXXVVII (sort)
= MCCCCCCCCCLLXXXII (combine, VV => X)
= MCCCCCCCCCCXXXII (... keep combining, LL => C)
= MMXXXII (... C{10} => M, nothing left to combine)
= MMXXXII (optionally, look for ways to re-write with the subtraction rule)
- bluesign 6y agoI think the practical way of thinking would be: - seeing L + L = C and converting CM to M ( basically striking L L and C ) - then V + V = X, ( striking Vs and add an X) Then write whats left: MMXXXII Then try to re-write.
- philwelch 6y agoI originally thought canonicalize was an important step, but it actually isn’t for humans. For humans, CCCCCCCCC requires a lot more tedious counting than CM or even DCCCC, leading to more errors than simply allowing the human to notice that CM+C=M.