一、 口算
12×2/3 = 8/9÷12= 18÷9/20 = 9/11×3=
3/20×4/9 = 4/15×15/16 = 5/6 ÷10= 7×5/14 =
9/40 ×2/3 = 12÷1/5 = 3/5 ÷3= 27÷ 9/20=
1/5÷1/3 = 6÷ 3/5 = 6/11 ÷2= 3/4 ÷ 4/3 =
二、 计算，能简便可以简便。
(5/7 - 5/8)÷5/32 24×(3/8 +1/4 ) ( 3/4+1/6 -3/24 )÷1/24
(1/4 - 1/9)×4×9 5/11 ÷9+6/11 ×1/9 42÷( 1/6÷2/9 )
三、 解方程
3/8X+1/4 = X- 1/7 X = 3/16 X-40%X=40
所需点数：0
