\[\boxed{\mathbf{537\ (537).}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[20 = 2 \cdot 2 \cdot 5,\ \]
\[50 = 5 \cdot 5 \cdot 2,\ \]
\[125 = 5 \cdot 5 \cdot 5,\ \]
\[64 = 2 \cdot 2 \cdot 2 \cdot 2 \cdot 2 \cdot 2.\]
\[\boxed{\mathbf{5}\mathbf{37}}\]
\[1)\ \frac{12}{23} = 0,52173 \approx 0,52\]
\[2)\ \frac{6}{43} = 0,1395\ldots \approx 0,14\]
\[3)\ \frac{8}{9} = 0,8888\ldots \approx 0,89\]
\[4)\ 5\frac{5}{16} = 5,3125 \approx 5,31\]
\[5)\ 1\frac{2}{7} = 1,2857\ldots \approx 1,29\]
\[6)\ 3\frac{1}{625} = 3,0016 \approx 3,00\]