解:原式=2.4x1.9+0.24x8.1
=2.4x1.9+2.4x0.81
=2.4x(1.9+0.81)
=2.4x2.71
=6.504
分析:主要考察拆分法和提取公因式的简便方法。
2.4 x 1.9 + 0.24 x 8.1
= 2.4 x (1.9 + 0.1 x 8.1)
= 2.4 x (1.9 + 0.81)
= 2.4 x 2.71
= 6.504
如果是:2.4 x 1.9 + 0.24 x 81
= 2.4 x 1.9 + 2.4 x 8.1
= 2.4 x (1.9 + 8.1)
= 2.4 x 10
= 24