奥数 简便运算41.2X8.1+11X9.25+53.7X1.9

奥数 简便运算41.2X8.1+11X9.25+53.7X1.9
奥数 简便运算
41.2X8.1+11X9.25+53.7X1.9

奥数 简便运算41.2X8.1+11X9.25+53.7X1.9
41.2×8.1+11×9.25+53.7×1.9
=41.2×8.1+11×9.25+(41.2+12.5)×1.9
=41.2×8.1+41.2×1.9+11×9.25+12.5×1.9
=41.2×(8.1+1.9)+11×(8+1.25)+12.5×1.9
=41.2×10+11×8+11×1.25+12.5×1.9
=412+11×8+1.1×12.5+12.5×1.9
=412+88+12.5×(1.1+1.9)
=412+88+37.5
=537.5