8:
0.13:2.6
5.6:
0.4km:40m.
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解:(1)8:,
=(8×5):(×5),
=40:8,
=5:1;
8:,
=5:1,
=5÷1,
=5;
(2)0.13:2.6,
=(0.13×100):(2.6×100),
=13:260,
=1:20;
0.13:2.6,
=1:20,
=1÷20,
=.
(3)5.6:,
=(5.6×5):(×5),
=28:14,
=2:1;
5.6:,
=2:1,
=2÷1,
=2;
(4)0.4km:40m,
=400m:40m,
=(400÷40):(40÷40),
=10:1;
0.4km:40m,
=10:1,
=10÷1,
=10.
解析分析:(1)根据比的基本性质,即比的前项和后项同时乘或除以一个相同的数(0除外)比值不变,进而把比化成最简比;
(2)根据求比值的方法,就用最简比的前项除以后项即得比值.
点评:此题考查化简比和求比值的方法,要注意区分:化简比的结果是一个比;而求比值的结果是一个数;还要注意无论是求比值还是化简比,比的前后项是名数的,都要先把单位化统一再计算.