算一算。30×20＝（）80&ti

算一算。4V7B;r-o7F9n5\'w4i/y;n6?*o;T:v,F0I9t2F

30×20＝9p,U3d*~;?(k4y*b/M(F:X8B3F4V7B;r-o7F9n5\'w4i/y;n6?*o;T:v,F0I9t2F

80×40＝9X9T8M/S4V7B;r-o7F9n5\'w4i/y;n6?*o;T:v,F0I9t2F

1－0.1＝7e4J1_6|/@4V7B;r-o7F9n5\'w4i/y;n6?*o;T:v,F0I9t2F

7.1－3.4＝5[-q2e1G8U.})m+I4H0r8H0w5Z4V7B;r-o7F9n5\'w4i/y;n6?*o;T:v,F0I9t2F