First, we will write MCMXII and MDCCCXLIV in numbers, i.e. MCMXII = 1000 + 900 + 10 + 2 = 1912 and MDCCCXLIV = 1000 + 800 + 40 + 4 = 1844. Now, 1912 - 1844 = 68. And 68 = LXVIII. Therefore, LXVIII should be subtracted from MCMXII roman numerals to get MDCCCXLIV. Wh...