Ask Siri to do maths for you
No matter how good of a mathematician you might be, having Siri on-hand to help with you simple and complex maths questions is always useful.
Simply open Siri and recite your equation to it. If the number is complex, make sure you say it at a slightly slower pace, so that Siri doesn't misunderstand it.
We found Siri to also correctly divide, multiply, subtract and add, with slightly more complicated equations too