28×30= 56×15= ×=1680
420÷28= 840÷15= 420÷28=
(24×2)×13=
(13 )×(24÷2)=312
(312×3)÷(24×3)=
(▲×6)÷(●×3)= (▲×)÷(●×5)= 16
(▲÷8)÷( ●÷)= 8 (▲÷12)÷( ●÷36)=
×=38.5
×=3.85
385÷=0.385
÷ 1 × ÷ 10×
10000999 1.87×0.951.87
÷ a×1.5a÷ (a>0)