1\4*4,5*1\5,8*3\8 ,6*3\4
1\4*4=1/4*4/1=1;/// 5*1\5=5/1*1/5=1;/// 8*3\8=8/1*3/8=3;/// 6*3\4=6/1*3/4=9/2=4 1/2
1/4-0.25 1/5-0.2 3/8-0.375 3/4-0.76 0.25*4.5*0.2=0.225 8*0.375=3 6*0.76=4.56