Question

二分之一乘以六分之一加十二分之一加上二十分之一加三十分之一用简便计算怎么？

Answer 1

1/2×1/6+1/12+1/20+1/30
=1/12+1/12+3/60+2/60
=5/60+5/60+3/60+2/60
=15/60
=0.25。

Answer 2

解：依题意得
1/2×1/6+1/12+1/20+1/30
＝1/12+1/12+1/20+1/30
＝1/6+1/30+1/20
＝5/30+1/30+1/20
＝1/5+1/20
＝4/20+1/20
＝1/4。

Answer 3

1/2*1/6+1/12+1/20+1/30
=1/12+1/12+1/20+1/30
=1/6+1/30+1/20
=1/5+1/20
=1/4=0.25

Answer 4

1/2x1/6+1/12+1/20+1/30
=1/2x1/6+1/12+(3/60+2/60)
=1/2x1/6+(1/12+5/60)
=1/2ⅹ1/6+1/6
=1/6x(1/2+1)
=1/6x3/2
=1/4。

Answer 5

1/2×1/6+1/12+1/20+1/30
＝10/60+3/60+2/60
＝15/60
＝3/20