1 直接算=6/7
2 =1.25*8*4*2.5=100
3 =3/4*(3.6+2/5)=3/4*4=3
4 =3*7/3-7/3*1/3=7/3*(3-1/3)=7/3*8/3=56/9
5 =3.7*(0.172+0.828)=3.7
6 =1/4*(18+12+10)=1/4*40=10
7 =10+3.8-3,8/2*5
=10-3.8(1/2*5-1)
=10-3.8*3/2
=10-5.7
=4.3
8 直接算=11/21
9 =7/9+2/9+6.28-4.28
=1+2=3
10 =2/3+2/3*5/3-3/5*5/3
=2/3*(1+5/3)-1
=16/9-1
=7/9