Ready to do some math? We're starting with 3867 and 8004 and adding them up.

Step 1: We'll start by adding the digits 7 & 4 in column 1 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 6 & 0 in column 2 and get 7.

Step 3: We'll start by adding the digits 8 & 0 in column 3 and get 8.

Step 4: We'll start by adding the digits 3 & 8 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 3867 + 8004 = 11871.

