Challenge Level

What are the prime factors of 10?

What are the prime factors of 100?

What are the prime factors of 1000?...

You could rewrite the eight fractions like this:

$$\frac23 \qquad \frac{2^2}5 \qquad \frac{17}{2\times5^2} \qquad \frac3{2^4} $$ $$\frac7{2^2 \times 3} \qquad \frac5{2^3} \qquad \frac{11}{2\times 7} \qquad \frac{2^3}{3 \times 5}$$

What do the fractions with terminating decimals have in common?