Not to worry, we've got 6419 and 6064. Let's get to adding them!

Step 1: We'll start by adding the digits 9 & 4 in column 1 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 1 & 6 in column 2 and get 8.

Step 3: We'll start by adding the digits 4 & 0 in column 3 and get 4.

Step 4: We'll start by adding the digits 6 & 6 in column 4 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

So, 6419 + 6064 = 12483.

