We've got two numbers: 4123 and 3768. Let's find their sum.

Step 1: We'll start by adding the digits 3 & 8 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 2 & 6 in column 2 and get 9.

Step 3: We'll start by adding the digits 1 & 7 in column 3 and get 8.

Step 4: We'll start by adding the digits 4 & 3 in column 4 and get 7.

So, 4123 + 3768 = 7891.

