17×40＝680,100－63＝37,3.2＋1.68＝4.88,2.8×0.4＝ 1.12 14－7.4＝6.6,1.92÷0.04＝48,0.32×500＝160,0.65＋4.35＝ 5 10－5.4＝4.6,4÷20＝0.2,3.5×200＝700,1.5－0.06＝1.44 0.75÷15＝0.05,0.4×0.8＝0.32,4×0.25＝1,0.36＋1.54＝2 1.01×99＝99.99,420÷35＝12,25×12＝300,135÷0.5＝270 3/4 + 1/4 =1,2 + 4/9 =22/9,3 - 2/3 =7/3,3/4 - 1/2= 1/4 1/6 + 1/2 -1/6 =1/2,7.5-(2.5+3.8)=1.2,7/8 + 3/8 =5/4 3/10 +1/5 =1/2,4/5 - 7/10 =1/10,2 - 1/6 -1/3 =1.5 0.51÷17＝0.03,32.8＋19＝51.8,5.2÷1.3＝4,1.6×0.4＝ 0.64 4.9×0.7＝3.43,1÷5＝0.2,6÷12＝0.5,0.87－0.49＝0.38