× = ×=0.1× = ×17=1.
1个8=( )个4=( )个2
( )×2=80( )×4=80( )×8=80
( )×2=72( )×4=72( )×8=72
( )×2=64( )×4=64( )×8=64
( )×2=56( )×4=56( )×8=56