333……33（998个3）×333……34（998个3）=?

=33...33(98个3)*33...33(98个3)+33...33(98个3)
=33...33(98个3)*[(3+1)+(30+10)+(300+100)+...+(3000+1000)]+33...33(98个3)-11...11(98个1)
=1000(98个0)+1000(99个0)+1000(100个0)+.+1000(196个0)+22...22(98个2)
=111...111(98个1)222..222(98个2)