We've got two numbers: 1445 and 2100. Let's find their sum.

Step 1: We'll start by adding the digits 5 & 0 in column 1 and get 5.

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

Step 3: We'll start by adding the digits 4 & 1 in column 3 and get 5.

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

So, 1445 + 2100 = 3545.

