\[\boxed{\mathbf{1.}}\]
\[32\ 000\ :100 = 320\]
\[8000\ :1000 = 8\]
\[1\ 050\ 000\ :100 = 10\ 500\]
\[25\ 400\ 000\ :10\ 000 = 2540\]
\[720\ 000\ :80 = 900\]
\[540\ 000\ :6000 = 90\]
\[6\ 300\ 000\ :700 = 9000\]
\[420\ 000\ :1400 = 300\]
\[\boxed{\mathbf{2.}}\]
\[\textbf{а)}\ a + b\]
\[4\ 815\ 679 + 234\ 826 =\]
\[= 5\ 050\ 505\]
\[\textbf{б)}\ c - d\]
\[6\ 003\ 040 - 244\ 445 =\]
\[= 5\ 758\ 595\]
\[\boxed{\mathbf{3.}}\]
\[= 56\ :8 + 60\ :12 - 0\ :7 =\]
\[= 7 + 5 - 0 = 12\]
\[\boxed{\mathbf{4.}}\]
\[1)\ (12 + 8) \cdot (3 + 4) - 8 \cdot 3 =\]
\[= 20 \cdot 7 - 24 = 140 - 24 =\]
\[= 116\ \left( см^{2} \right) - площадь\ \]
\[закрашенной\ фигуры.\]
\[2)\ 12 + 3 + 8 + 4 + (12 + 8) + (3 + 4) =\]
\[= 27 + 20 + 7 = 54\ (см) -\]
\[периметр\ закрашенной\ фигуры.\]
\[Ответ:116\ см^{2};\ \ 54\ см.\]
\[\boxed{\mathbf{5.}}\]
\[70\ 000 \cdot 100\ :1000 = 7000\]