If you've ever wanted a scientific calculator app on iPhone, don't fret—your iPhone already comes with one built in. Apple's Calculator app includes a scientific mode that has been hiding in plain sight since 2008. Here's how to use it.

Open the iPhone's Scientific Calculator

First, open the "Calculator" app. If you can't find it, swipe downward with one finger in the middle of the screen to see a search bar. Type "calc" and select the "Calculator" app icon when it appears.

Once Calculator opens, you'll probably see a screen like this. It's a simple interface with a grid of numbers and basic mathematical operators. Hardly scientific at all!

To enter scientific calculator mode, rotate your iPhone 90 degrees until it is in landscape orientation. The Calculator app will automatically adjust to fit the wide orientation of the screen, and new scientific calculator buttons will be added to the display.

If your calculator doesn't change into scientific mode when you rotate your iPhone, then it's likely that you have orientation lock enabled. To disable it, pull up Control Center and tap the orientation lock icon until it is no longer highlit.

Once orientation lock is turned off, rotate your iPhone again while running the Calculator app, and you'll see the scientific mode in all its widescreen glory. A brave new world of more complex math has now opened up to you. Have fun with exponents!