If the denominator of the simplest fraction contains only the prime factor () or (), then the fraction can be reduced to a finite number. Why?

If the denominator of the simplest fraction contains only the prime factor () or (), then the fraction can be reduced to a finite number. Why?

2 or 5

Judgment question: a fraction, if the denominator contains other qualitative factors than 2 and 5, can not be converted into a finite decimal ()

Wrong
If the denominator contains a prime factor other than 2 and 5, it cannot be reduced to a finite decimal
If it's not the simplest, we can reduce it. It's possible to reduce the prime factors other than 2 and 5 in the denominator. After reduction, it can be reduced to a finite number

A simplest fraction, whose denominator contains only two and five prime factors, can be reduced to a finite number______ ．

The way to judge whether a fraction can be transformed into a finite decimal: if the denominator of the simplest fraction contains only the prime factor 2 or 5, the fraction can be transformed into a finite decimal