Symbolab Math Solver Step by step calculations This is a pay for app that is worth the annual investment as it will allow access to number line animations as well as custom quizzes to allow you to practise those areas you are having difficulty with.  Also provides basic Chemistry help with balancing formulas.

fxSolver fxSolver is an free online math solver, equation library, graphing calculator and science/engineering problem helper. To get started, add some formulas, fill in any input variables and press "Solve.“

Microsoft Math A free app to help with school math problems

Mathway Mathway is a freemium math solving app that helps you find the solutions to any math problem you can imagine.

Photomath Photomath is a mobile app that will give you the ability to test your equations through a simple calculator interface that will fully explain the solution in a step-by-step fashion. Read more about Photomath

WolframAlpha WolframAlpha brings expert-level knowledge and capabilities to the broadest possible range of people—spanning all professions and education levels.