We are presented with 7242 and 3580. Let's work out the sum.

Step 1: We'll start by adding the digits 2 & 0 in column 1 and get 2.

Step 2: We'll start by adding the digits 4 & 8 in column 2 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 2 & 5 in column 3 and get 8.

Step 4: We'll start by adding the digits 7 & 3 in column 4 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

So, 7242 + 3580 = 10822.

