100-9•8+64-8•6=, 68+32:4•8-99=, 72:9•6+52=, 400-355+7•4•3•0=

100 - 9 * 8 + 64 - 8 * 6 = 100 - 72 + 64 - 48 = 28 + 64 - 48 = 92 - 48 = 44;

68 + 32 : 4 * 8 - 99 = 68 + 8 * 8 - 99 = 68 + 64 - 99 = 33;

72 : 9 * 6 + 52 = 8 * 6 + 52 = 48 + 52 = 100;

400 - 355 + 7 * 4 * 3 * 0 = 45 + 28 * 3 * 0 = 45 + 84 * 0 = 45 + 0 = 0.