OK, let's do this. We've got 5337 and 3117 and we're adding them all together.

Step 1: We'll start by adding the digits 7 & 7 in column 1 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 3 & 1 in column 2 and get 5.

Step 3: We'll start by adding the digits 3 & 1 in column 3 and get 4.

Step 4: We'll start by adding the digits 5 & 3 in column 4 and get 8.

So, 5337 + 3117 = 8454.

