简便方法（36+7）×53+40×53=43×53+40×53=（40+40）*53+3*53=4240+159=4399
4 399
36×53+40×53+7×53=53*(36+40+7)=53*83=4399
36×53+40×53+7×53=53(36+40+7)=53*83=4399
