Alexa my math teacher is an Alexa skill that helps all students solve most math problems, whether simple or complex. Being a student myself I would have really appreciated such a companion to talk to and to help me solve problems. To make it work the user has to say something like "Alexa ask math teacher what is the value of Pi".
The Alexa skill uses AWS Lambda to make the API call to WolframAlpha. Code in the code section.
The skill name is "Mathy: The math teacher" and is currently pending certification.