There are two basic ways to do fractions on your iPhone calculator. Here's what you need to know to use the built-in app.

How to Divide Fractions on the Google Calculator. Google Calculator is an online tool offered by Google that lets you use its website to do basic math calculations such as addition and subtraction.

On Android, consider checking out Graph 89 Free —though you’ll need a .ROM image for it to work (something you can extract from your existing graphing calculator or surely find elsewhere).