Question

999点9×777点8 333点3×666点六简便计算？

Answer 1

999.9×777.8+333.3×666.6 把666.6化为3×222.2
=999.9×(777.8+222.2)

=999.9×1000
=999900

Answer 2

999.9×777+333.3×666
=333.3×3×777+333.3×3×222
=(333.3×3)×(777+222)
=999.9×999
=(1000-0.1)×999
=999000-99.9
=999000-100+0.1
=998900.1