0.7*12.5*8. 196.7/2.5/4. 4.6*12+5.5*12—0.1*12
=0.8*12.5*0.7 =196.7/（2.5*4）. =12*（4.6+5.5—0.1）
=10*0.7 =196.7/10. =12*10
=7 =19.7. =120
64.8*100.1 7.5+47.8+2.5
=64.8*（100+0.1） =7.5+2.5+47.8
=64.8*100+64.8*0.1 =10+47.8
=6840+6.48 =57.8
=6846.48
注：/等于除以,*等于乘以 0.7*12.5*8. 196.7/2.5/4. 4.6*12+5.5*12—0.1*12
=0.8*12.5*0.7 =196.7/（2.5*4）. =12*（4.6+5.5—0.1）
=10*0.7 =196.7/10. =12*10
=7 =19.7. =120
64.8*100.1 7.5+47.8+2.5
=64.8*（100+0.1） =7.5+2.5+47.8
=64.8*100+64.8*0.1 =10+47.8
=6840+6.48 =57.8
=6846.48
注：/等于除以,*等于乘以