We've got two numbers: 100 and 1643. Let's find their sum.

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

Step 2: We'll start by adding the digits 0 & 4 in column 2 and get 4.

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

Step 4: We'll start by adding the digits 0 & 1 in column 4 and get 1.

So, 100 + 1643 = 1743.

