\[\boxed{\mathbf{Вариант\ 2.}}\]
\[\boxed{\mathbf{1.}}\]
\[398,\ 399,\ 400,\ 401.\]
\[\boxed{\mathbf{2.}}\]
\[699 + 1 = 700\]
\[439 + 1 = 440\]
\[299 + 1 = 300\]
\[560 - 1 = 559\]
\[800 - 1 = 799\]
\[710 - 1 = 709\]
\[\boxed{\mathbf{3.}}\]
\[205 = 200 + 5\]
\[483 = 400 + 80 + 3\]
\[\boxed{\mathbf{4.}}\]
\[4\ м = 400\ см\]
\[55\ дм = 550\ см\]
\[8\ м\ 5\ см = 805\ см\]
\[720\ см = 7\ м\ 2\ дм\]
\[358\ см = 3\ м\ 5\ дм\ 8\ см\]
\[900\ мм = 9\ дм\]
\[\boxed{\mathbf{5.}}\]
\[203 < 302\]
\[438 < 458\]
\[873 > 783\]
\[650 > 560\]
\[\boxed{\mathbf{6.}}\]
\[200 + 90 + 9 = 299\]
\[865 - 60 - 5 = 800\]
\[907 + 80 = 987\]
\[480 - 400 = 80\]
\[432 - 32 = 400\]
\[550 - 50 = 500\]
\[\boxed{\mathbf{7.}}\]
\[873 + 1 = 874 = 800 + 70 + 4\]