Let's solve this addition problem. We have 7578 and 5428, and we need to add them together.

Step 1: We'll start by adding the digits 8 & 8 in column 1 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 7 & 2 in column 2 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 5 & 4 in column 3 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 7 & 5 in column 4 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

So, 7578 + 5428 = 13006.

