We are presented with 7003 and 7867. Let's work out the sum.

Step 1: We'll start by adding the digits 3 & 7 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 0 & 6 in column 2 and get 7.

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

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

So, 7003 + 7867 = 14870.

