Math Problem Solver

$$244 - 121=123$$

$$\begin{aligned} \mathtt{2}\mathtt{4}\mathtt{4}\\ \mathtt{-\phantom{0}}\mathtt{1}\mathtt{2}\mathtt{1}\\ \hline \mathtt{1}\mathtt{2}\mathtt{3} \end{aligned}$$

$3$ is the digit in the $10^{0}$ place. $4 \times 10^{0} - 1 \times 10^{0} = 3 \times 10^{0}$.

$2$ is the digit in the $10^{1}$ place. $4 \times 10^{1} - 2 \times 10^{1} = 2 \times 10^{1}$.

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