÷= ×= += -=
6×= 2-= 12÷= ×3÷×3=
9.5-1.05 = 0.8- = ×0=
19×(4×25)( )
(4×19)×25( )
(11×8)×125( )
11×(8×125)( )
(4×25)×(8×125)( )
(4×8)×25×125( )