Math Problem Solver

$$180 - 71=109$$

$$\begin{aligned} \mathtt{1}\overset{\mathtt{{\scriptscriptstyle 7}}}{\cancel{\mathtt{8}}}\overset{\mathtt{{\scriptscriptstyle 10}}}{\cancel{\mathtt{0}}}\\ \mathtt{-\phantom{0}}\phantom{0}\mathtt{7}\mathtt{1}\\ \hline \mathtt{1}\mathtt{0}\mathtt{9} \end{aligned}$$

Borrow $10^{1}$, resulting in $7$ in the $10^{1}$ place, and $10$ in the $10^{0}$ place.

$9$ is the digit in the $10^{0}$ place. $10 \times 10^{0} - 1 \times 10^{0} = 9 \times 10^{0}$.

$0$ is the digit in the $10^{1}$ place. $7 \times 10^{1} - 7 \times 10^{1} = 0 \times 10^{1}$.

$1$ is the digit in the $10^{2}$ place. $1 \times 10^{2} - 0 \times 10^{2} = 1 \times 10^{2}$.