Okay, we are given 9640 and 51. Let's add them up step by step.

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

Step 2: We'll start by adding the digits 4 & 5 in column 2 and get 9.

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

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

So, 9640 + 51 = 9691.

