(38×56×64)÷ (19× 28× 16)
=(38/19)*(56/28)*(64/16)
=2*2*4=16
3333× 3334
=3333*(3333+1)
=3333^2+3333
=11108889+3333
=11112222
(333…n个…3)^2=111……(n-1个)0888……(n-1个)9