Column Addition and Column Subtraction

Using column addition: $5+8=13$, write 3 and carry 1. Then $6+4+1=11$, giving 113.

Using column subtraction: $4-9$ needs borrowing, making it $14-9=5$. Then $5-1-2=2$, giving 25.

Using column addition: $4+3=7$, $5+2=7$, $3+1=4$. No carrying needed, giving 477.

Using column subtraction: $2-8$ needs borrowing, so $12-8=4$. Then $5-1-2=2$ and $7-4=3$, giving 324.

Using column subtraction: $9-4=5$, then $3-8$ needs borrowing so $13-8=5$, then $6-1-2=3$, giving 355.

Using column addition: $5+6=11$, carry 1. Then $8+3+1=12$, carry 1. Then $2+7+1=10$, carry 1. Finally $1+0+1=2$, giving 2021.