一.32.5*48.7-168*3.6
=1582.75-604.8
=977.95
二.1993*199.2-199.2*199.1
=199.2[1993-199.1]
=199.2*1793.9
=357344.88
三.1946又1/3+345又1/8-15又1/2
=1946+1/3+345+1/8-15-1/2
=[1946+345-15]+[1/3+1/8-1/2]
=2276-1/24
=2275又23/24