Question

用简便方法计算 0.28×8.6+7.2×0.86 999×778+333×666 怎样写?

Answer 1

0.28×8.6+7.2×0.86

=0.28*8.6+0.72*8.6

=(0.28+0.72)*8.6

=1*8.6

=8.6

999×778+333×666

=999*778+333*3*222

=999*(778+222)

=999*1000

=999000