\[\boxed{\mathbf{937}.\ }\]
\[18 \cdot 5\ мм = 90\ мм = 9\ см.\]
\[\frac{3}{18} = \frac{1}{6};\]
\[\frac{6}{18} = \frac{3}{9} = \frac{2}{6} = \frac{1}{3};\]
\[\frac{9}{18} = \frac{3}{6} = \frac{1}{2};\]
\[\frac{12}{18} = \frac{2}{3} = \frac{4}{6};\]
\[\frac{15}{18} = \frac{5}{6};\]
\[\frac{8}{9} = \frac{16}{18}.\]