Here we go! We're going to add 4209 and 9947 together.

Step 1: We'll start by adding the digits 9 & 7 in column 1 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 0 & 4 in column 2 and get 5.

Step 3: We'll start by adding the digits 2 & 9 in column 3 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 4 & 9 in column 4 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

So, 4209 + 9947 = 14156.

