\[\boxed{\mathbf{210.}}\]
\[1)\ 130 + 20 = 150\]
\[20 + 130 = 150\]
\[251 + 30 = 282\]
\[30 + 251 = 281\]
\[От\ перемены\ мест\ слагаемых\ \]
\[сумма\ не\ меняется.\]
\[2)\ 20 + 150 = 170\]
\[30 + 210 = 240\]
\[40 + 320 = 360\]
\[50 + 430 = 480\]
\[20 + 325 = 345\]
\[40 + 216 = 256\]
\[60 + 123 = 183\]
\[70 + 111 = 181\]