Question

53,5*35,3+53,3*43,2+78,5*46,5 简便算法 中间的逗号是点

Answer 1

53.5*35.3+53.3*43.2+78.5*46.5

=53.5*35.3+（53.5-0.2）*43.2+78.5*46.5

=53.5*（35.3+43.2）-0.2*43.2+78.5*46.5

=53.5*78.5+78.5*46.5-0.2*43.2

=78.5*100-8.64

=7850-8.64

=7841.56