Replace each * by the correct digit in each of the following:

$\begin{matrix} & 1 & 7 & 0 & 0 & \ast & 4 \ - & & 8 & \ast & \ast & 4 & 7 \ \hline & & \ast & 8 & 6 & 6 & \ast \ \hline \end{matrix}$

$\begin{matrix} & 1 & 7 & 0 & 0 & \ast & 4 \ - & & 8 & \ast & \ast & 4 & 7 \ \hline & & \ast & 8 & 6 & 6 & \ast \ \hline \end{matrix}$

Units column: 4 - 7 requires borrowing. So, 10 + 4 - 7 = 7. The * in the result = 7. (Borrow 1)

Tens column: After borrowing, * - 1 - 4 = 6 requires borrowing. So, * + 10 - 1 - 4 = 6, which gives * = 1 (in the minuend). (Borrow 1)

Hundreds column: After borrowing, 0 - 1 - * = 6 requires borrowing. So, 10 + 0 - 1 - * = 6, which gives * = 3 (in the subtrahend). (Borrow 1)

Thousands column: After borrowing, 0 - 1 - * = 8 requires borrowing. So, 10 + 0 - 1 - * = 8, which gives * = 1 (in the subtrahend). (Borrow 1)

Ten thousands column: After borrowing, 7 - 1 - 8 requires borrowing. So, 10 + 7 - 1 - 8 = 8. The * in the result = 8. (Borrow 1)

Hundred thousands column: 1 - 1 = 0, The leftmost digit becomes 0, which is omitted.

Hence, the completed subtraction is:

$\begin{matrix} & 1 & 7 & 0 & 0 & 1 & 4 \ - & & 8 & 1 & 3 & 4 & 7 \ \hline & & 8 & 8 & 6 & 6 & 7 \ \hline \end{matrix}$

Verification: 170014 - 81347 = 88667.