We are presented with 5128 and 3542. Let's work out the sum.

Step 1: We'll start by adding the digits 8 & 2 in column 1 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 2 & 4 in column 2 and get 7.

Step 3: We'll start by adding the digits 1 & 5 in column 3 and get 6.

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

So, 5128 + 3542 = 8670.

