Từ các số : `4;16;64;256;1024,` ta lập được các tích : `4.256=16.64; 4.1024=16.256; 16.1024=64.256`
`4.256=16.64⇒`$\begin{cases}\dfrac{4}{16}=\dfrac{64}{256}\\\\\dfrac{16}{4}=\dfrac{256}{64}\\\\\dfrac{4}{64}=\dfrac{16}{256}\\\\\dfrac{64}{4}=\dfrac{256}{16}\end{cases}$
`4.1024=16.256⇒`$\begin{cases}\dfrac{4}{16}=\dfrac{256}{1024}\\\\\dfrac{16}{4}=\dfrac{1024}{256}\\\\\dfrac{4}{256}=\dfrac{16}{1024}\\\\\dfrac{256}{4}=\dfrac{1024}{16}\end{cases}$
`16.1024=64.256⇒`$\begin{cases}\dfrac{16}{64}=\dfrac{256}{1024}\\\\\dfrac{64}{16}=\dfrac{1024}{256}\\\\\dfrac{16}{256}=\dfrac{64}{1024}\\\\\dfrac{256}{16}=\dfrac{1024}{64}\end{cases}$
