27 + 0.91 + 0.39

The sum of 27, 0.91, and 0.39 is 28.3.

To add these numbers, follow these steps:

Step 1: Add the whole numbers together:
27 + 0 = 27

Step 2: Add the decimal parts together:
0.91 + 0.39 = 1.3

Step 3: Add the results from step 1 and step 2 together:
27 + 1.3 = 28.3

Therefore, the sum of 27, 0.91, and 0.39 is 28.3.

To calculate the sum of 27, 0.91, and 0.39, you simply add them together:

27 + 0.91 + 0.39 = 28.3

So the answer is 28.3.