We are presented with 2291 and 1400. Let's work out the sum.

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

Step 2: We'll start by adding the digits 9 & 0 in column 2 and get 9.

Step 3: We'll start by adding the digits 2 & 4 in column 3 and get 6.

Step 4: We'll start by adding the digits 2 & 1 in column 4 and get 3.

So, 2291 + 1400 = 3691.

