Typing math problems in calculator can be tedious, especially when you have complex equations to solve. If you want to write out your problems instead, then you need to check out MyScript Calculator from Vision Objects.
MyScript Calculator provides a large canvas on which you can write out your equation. When you are done writing, the app automatically will convert your writing into type-written numbers and calculate the answer for you. If you don't like the automatic answer, a new feature recently added to the app allows you to turn off auto-answer and use a "Calculate" button instead. The app supports the standard operations such as multiplication and division as well as a wide array of complex functions used in trigonometry and calculus.
One of the useful features of MyScript Calculator is its ability to solve for unknowns. Just insert an "?" into an equation with its answer and the app will fill in the correct value for the unknown. It also supports gestures which allow you to strike-through or scratch out numbers you want to remove from your calculation.
MyScript Calculator was recently updated for iOS 7 and includes a new new operators (n-root, hyperbolic functions) and new rounding options that let you choose between rounded and truncated results. It is available for free from the iOS App Store and works on both the iPad and iPhone.