小数乘法简便运算 一、乘法凑整 例1 4×2.3×2.5 8×0.7×12.5 小试身手 0.25×8.5×4 4.36 2.5×0.8×1.25×0.4 0.4 例2 0.25×3.6 5.6 小试身手 0.125×7.2 2.5 0.25×3.2×12.5 4.1 ×12.5×0.8 0.125×0.96×8 ×1.3×8×2 1.25×0.9×8××0.125 ×1.2×2 1.6×1.25×4.7 ×2.5×2.8 1.25×6.2×2.4 12.5 二、乘法分配律 例1 4.8×10.1 0.85×9.9 小试身手 102×0.43 3.2×10.1 3.5 9.5×0.9 100.04×4.5 0.25 三、乘法分配律的逆运算(提取公因数) 例1 3.72×3.5+6.28×3.5 15.6 例2 9.7×99+9.7 6.3 小试身手 4.6×0.9+0.1×4.6 2.95×101-2.95 3.65 ×9.8 ×99.8 ×2.1-15.6×1.1 ×101-6.3 ×0.47-0.37×3.65 0.33×46+54×0.33 7.09×1.08-7.09×0.08 6.9×99+6.9 8.7×17.4-7.4×8.7 4.2×1.25+4.2×1.75 0.25×39+0.25 0.25×39+0.25 2.5 5.41×0.6-4.41×0.6 8.4 9.2×99 2.37 9.9×3.7 1.8 0.111×4.9+0.111×2.1 99 综合练习 ×4.4×3 3.2×20.2 ×100.2 5.7×1.25×1.6 ×6.3+2.37×3.7 8.6×101-8.6 ×9+1.8 5×1.03×0.2 ×4.9+4.9 54.7×6.29-6.29×44.7 本文来源:https://www.wddqw.com/doc/bf4df649f31dc281e53a580216fc700abb6852fd.html