简便计算
9999 × 7778 + 3333 × 6666
= 9999 × 7778 + 9999 × 2222
= 9999 × (7778 + 2222)
= 9999 × 10000
= 99990000
9999*7778+3333*6666
=9999*7777+3333*6666+9999
=(9*7+6*3)*1111*1111+9999
=81*1111*1111+9999
=9999*9999+9999
=9999*(9999+1)
=99990000
原式
=9999x7778+3333x3x2222
=9999x7778+9999x2222
=9999x(7778+2222)
=9999x10000
=99990000
9999*7778+3333*6666
=9999*7778+3333*3*2222
=9999*7778+9999*2222
=9999*(7778+2222)
=9999*10000
=99990000
9999=10000-1
3333*6666=(3*1111)*6666