用简便方法计算
①0.4×1.36×2.5??????????????? ②0.45×101?????????????? ③3.8×4.6+4.6×6.2.
网友回答
解:①0.4×1.36×2.5,
=1.36×(0.4×2.5),
=1.36×1,
=1.36;
②0.45×101,
=0.45×100+0.45×1,
=45+0.45,
=45.45;
③3.8×4.6+4.6×6.2,
=(3.8+6.2)×4.6,
=10×4.6,
=46.
解析分析:①0.4×1.36×2.5,运用乘法交换律和结合律进行简算;②0.45×101,运用乘法分配律进行简算;③3.8×4.6+4.6×6.2.?运用乘法分配律进行简算.
点评:此题考查的目的是理解掌握乘法的运算定律,并且能够灵活运用乘法的运算定律对小数四则混合运算进行简便计算.