Question

41.2*8.1＋11*1.25＋53.7*1.9 如何简便计算?（脱式）

Answer 1

41.2*8.1+11*1.25+53.7*1.9

=41.2*8.1+53.7*(10-8.1)+11*1.25

=41.2*8.1+53.7*10-53.7*8.1+11*1.25

=53.7*10-(53.7-41.2)*8.1+11*1.25

=537-12.5*8.1+1.1*12.5

=537-12.5*(8.1-1.1)

=537-87.5

=449.5