OK, let's do this. We've got 1090 and 7201 and we're adding them all together.

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

Step 2: We'll start by adding the digits 9 & 0 in column 2 and get 9.

Step 3: We'll start by adding the digits 0 & 2 in column 3 and get 2.

Step 4: We'll start by adding the digits 1 & 7 in column 4 and get 8.

So, 1090 + 7201 = 8291.

