这样算最简便:
999*222+333*334
=333*3*222+333*334
=333*(666+334)
=333*1000
=333000
999×222+333×334
=(333×3)×222+333×334
=333×(3×222)+333×334
=333×666+333×334
=333×(666+334)
=333×1000
=333000
999*222+333*334=(1000-1)*222+333*334
=1000*222-222+333*334
=1000*222-111*2+111*3*334
=1000*222-111*2+111*1002
=1000*222+111*(1002-2)
=1000*222+1000*111
=1000*(222+111)
=1000*333
=333000