270/45=30*9/5*9=30/5=6

12* 105= 12*5*2 1=60*2 1= 1260

48*25=6*8*5*5=30*40= 1200

85*99+85=85(99+ 1)=8500

99*56+56=(99+ 1)56=5600

85*20 1-85=85(20 1- 1)= 17000

99*63=63* 100-63=6300-63=6237

Hope to adopt.