用简便方法计算. 5/12×1/13-1/4÷13 3.5×98+35×0.2.
问题描述:
用简便方法计算.
×5 12
-1 13
÷13 1 4
3.5×98+35×0.2.
答
①
×5 12
-1 13
÷13 1 4
=
×5 12
-1 13
×1 4
1 13
=(
-5 12
)×1 4
1 13
=
×1 6
1 13
=
1 78
②3.5×98+35×0.2
=35×9.8+35×0.2
=35×(9.8+0.2)
=35×10
=350