\[\boxed{\mathbf{2}\mathbf{.}\mathbf{88}}\]
\[\textbf{а)}\ 7 + 8 = 15\]
\[\textbf{б)}\ 30 + 5 = 35\]
\[\textbf{в)}\ 500 + 8 = 508\]
\[\textbf{г)}\ 2000 + 700 = 2700\]
\[\textbf{д)}\ 30\ 070 + 300 = 30\ 370\]
\[\textbf{е)}\ 1\ 000\ 000 + 17 = 1\ 000\ 017\]