\[\boxed{\mathbf{490.}}\]
\[1)\ 260\ :2 = 130\]
\[264\ :2 = 132\]
\[2)\ 420\ :2 = 210\]
\[210 \cdot 2 = 420\]
\[428\ :2 = 214\]
\[214 \cdot 2 = 428\]
\[360\ :3 = 120\]
\[120 \cdot 3 = 360\]
\[369\ :3 = 123\]
\[123 \cdot 3 = 369\]
\[840\ :2 = 420\]
\[420 \cdot 2 = 840\]
\[846\ :2 = 423\]
\[423 \cdot 2 = 846\]
\[690\ :3 = 230\]
\[230 \cdot 3 = 690\]
\[609\ :3 = 203\]
\[203 \cdot 3 = 609\]