Evaluate 30-18

Set up the subtraction problem in long subtraction format.

Borrow ${\displaystyle 10}$ from the digit in the next column to the left. Add the borrowed ${\displaystyle 10}$ to ${\displaystyle 0}$. Reduce the number that was borrowed from by ${\displaystyle 1}$.

Subtract ${\displaystyle 8}$ from ${\displaystyle 10}$.

Subtract ${\displaystyle 1}$ from ${\displaystyle 2}$.