Not to worry, we've got 8723 and 641. Let's get to adding them!

Step 1: We'll start by adding the digits 3 & 1 in column 1 and get 4.

Step 2: We'll start by adding the digits 2 & 4 in column 2 and get 6.

Step 3: We'll start by adding the digits 7 & 6 in column 3 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 0 in column 4 and get 9.

So, 8723 + 641 = 9364.

