Math Problem Solver

$$42 + 29=71$$

$$\begin{aligned} \overset{\mathtt{1}}{\mathtt{4}}\mathtt{2}\\ \mathtt{+\phantom{0}}\mathtt{2}\mathtt{9}\\ \hline \mathtt{7}\mathtt{1} \end{aligned}$$

$1$ is the digit in the $10^{0}$ place. $2 \times 10^{0} + 9 \times 10^{0} = 11 \times 10^{0} = 1 \times 10^{1} + 1 \times 10^{0}$.$1 \times 10^{1}$ carries to the $10^{1}$ place.

$7$ is the digit in the $10^{1}$ place. $1 \times 10^{1} + 4 \times 10^{1} + 2 \times 10^{1} = 7 \times 10^{1}$.