Bing has been supporting mathematical queries for a long time. For example, you can search for 100*9 and get 900 directly on the top of the page. Google also has similar feature but with interactive calculator which lets you to do mathematical queries with a calculator like UI. Now, Bing has added the same feature where you can do your own queries within your search results page with the calculator like UI. See the image above.
For example, try this out yourself here.