If you type a simple query like 4+2 in the search box, Google's built-in calculator will evaluate the expression and display the answer atop the search results.

When you type a US Zip Code like 10005 (for Downtown Manhattan, NY), Google will display a Google Map snapshot of that location.

But when a query resembles a Zip Code as well as a Maths expression, Google will display the Google Maps image plus the result of the calculation as you seen in the screenshot below:



You get such results when the maths expression matches a US Zip Code with the 4 digit add-on code (Zip + 4) [thanks anon]