五年级上册数学《行程问题之火车过桥问题》例题解析

五年级上册数学《行程问题之火车过桥问题》例题解析


简介:
(1)2.64×1.7-2.64×0.7 =2.64×(1.7-0.7) =2.64×1 =2.64 (2)31.5×1.07-3.15×0.7 =3.15×10.7-3.15×0.7 =3.15×(10.7-0.7) =3.15×10 =31.5 (3)2.7×5.7-2.7+5.3×2.7 =2.7×(5.7-1+5.3) =2.7×10 =27