112乘31加56乘38用简便方法计算
210乘34加33乘105减105用简便方法计算
112乘31加56乘38用简便方法计算
210乘34加33乘105减105用简便方法计算
112x31+56x38
=56x2x31+56x38
=56x(62+38)
=56x100
=5600
210x34+33x105-105
=105x2x34+33x105-105
=105x(68+33-1)
=105x100
=10500
112x31+56x38
=56x2x31+56x38
=56x(62+38)
=56x100
=5600
210x34+33x105-105
=105x2x34+33x105-105
=105x(68+33-1)
=105x100
=10500