Evaluate 15*7

Multiply ${\displaystyle 7}$ by ${\displaystyle 5}$. Place the ones digit ${\displaystyle \left(5\right)}$ in the result line and carry the tens digit ${\displaystyle \left(3\right)}$. There is one result line for each digit in ${\displaystyle 7}$.

Multiply ${\displaystyle 7}$ by ${\displaystyle 1}$ and add the carried ${\displaystyle 3}$. Place the ones digit ${\displaystyle \left(0\right)}$ in the result line and carry the tens digit ${\displaystyle \left(1\right)}$. There is one result line for each digit in the ${\displaystyle 7}$.

Add the numbers in each column. In this case, add ${\displaystyle 5}$, then place the ${\displaystyle 5}$ in the result line.

Add the numbers in each column. In this case, add ${\displaystyle 0}$, then place the ${\displaystyle 0}$ in the result line.

Add the numbers in each column. In this case, add ${\displaystyle 1}$, then place the ${\displaystyle 1}$ in the result line.