Exercises: Subtraction

$23-18=$

Subtract from right to left. First, subtract the ones digit. Since $3$ is smaller than $8$, you need to calculate $13-8=5$ instead and "memorize" a 1 at the tens digit.

$\begin{array}{l}23\\ \underline{-1_{1}8}\\ 5\end{array}$

Now subtract the tens: $2-(1+1)=0$

The result is therefore $5$.

$45-29=$

$\begin{array}{l}45\\ \underline{-2_{1}9}\\ 6\end{array}$

Subtract from right to left. First, subtract the ones digit. Since $9$ is larger than $5$ you need to calculate $15-9=6$ instead and "memorize" a 1 at the tens digit.

$\begin{array}{l}45\\ \underline{-2_{1}9}\\ 16\end{array}$

Now subtract the tens: $4-(2+1)=1$.

The result is therefore $16$.

$14-10=$

Calculate from right to left. Subtract the ones first: $4-0=4$.

$\begin{array}{l}14\\ \underline{-10}\\ 4\end{array}$

Now subtract the tens: $1-1=0$.

The result is therefore $4$.

$19-15=$

Subtract from left to right. Subtract the ones first: $9-5=4$.

$\begin{array}{l}19\\ \underline{-15}\\ 4\end{array}$

Now subtract the tens: $1-1=0$.

The result is therefore $4$.

$57-46=$

Subtract from left to right. Subtract the ones first: $7-6=1$.

$\begin{array}{l}57\\ \underline{-46}\\ 1\end{array}$

Now subtract the tens: $5-4=1$.

$\begin{array}{l}57\\ \underline{-46}\\ 11\end{array}$

The result is therefore $11$.