问题
解答题
用简便方法计算
①0.4×1.36×2.5 ②0.45×101 ③3.8×4.6+4.6×6.2.
答案
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.
用简便方法计算
①0.4×1.36×2.5 ②0.45×101 ③3.8×4.6+4.6×6.2.
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.