1) 62456715+548185=63004900
2) 63004900:700=90007
3)80450:5=16090
4) 16090*300=4827000
5) 63004900-4827000=58177900
40 1/2:9 = 81/2:9 = 81/2 * 1/9 = 9/2
2 * 9/2 = 9
6 52/100 - 11 1/50 = 652/100 - 551/50 = 652/100 - 1102/100 = - 450/100 = -45/10
9:(-45/10) = 9*(-10/45) = -10/5 = -2