Converting decimals to fractions example 3 | Decimals | Pre-Algebra | Khan Academy

Converting this decimal results in a fraction that needs to be simplified. Can you help us?

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0.36 を分数として書くことができるか
やってみましょう．

小数を分数に変換するにはいくつかの方法があります．
私の一番好きな方法では，

0.36 というのは 100 分の 36 と同じことです．
または，これを考える方法は，

これが 100 分の1の位です．

ここが 10 分の1の位です．あるいはこれを 30 個の 100 分の 1 と見ることもできます．これは 3 個の 10 分の 1 でもあり，30 個の100 分の 1 でもあります．

するとこれは 36 個の 100 分の 1 と同じことです．または，これは「100 分の 36」でもあります．

もうこの数を分数として表現できました．次にこれを約分して簡単にします．なぜならこれら 36 と 100 の数には共通する因数，公約数があるからです．

両方の数は 4 で割れます．ですから分子を4で割り，分母を4 で割ることができます．同じことを分子と分母の両方にします．そうしても分数の値は変わりません．

36 を 4 で割ると 9 です．100 を 4 で割ると 25 です．

この2つの数にはもう共通の因数，
公約数はないようです．

これが約分した既約の形です．できました．