56乘以199加56怎么简便?201乘以38减38怎么简便?

问题描述:

56乘以199加56怎么简便?201乘以38减38怎么简便?

56*199+56 = 56*(199+1) = 56*200 = 11200
201*38-38 = (201-1)*38 = 200*38 = 7600