\[\boxed{\mathbf{252.}}\]
\[420 + 310 > 420 + 130\]
\[322 + 133 = 133 + 322\]
\[565 + 30 < 565 + 330\]
\[640 - 530 < 640 - 520\]
\[755 - 420 < 755 - 402\]
\[888 - 103 > 888 - 123\]