Wolfram Alpha is an online service that answers factual queries directly by computing the answer from externally sourced "curated data", rather than providing a list of documents or web pages that might contain the answer as a search engine might.
Photomath is a mobile application described as a "camera calculator", which utilizes a phone's camera to recognize mathematical equations and to display the step-by-step solution onscreen.
Khan Academy is a non-profit educational organization created in 2008 by Salman Khan with the goal of creating a set of online tools that help educate students. The organization produces short lessons in the form of videos. Its website also includes supplementary practice exercises and materials for educators.
Using Your Calculator to Calculate Fractions and Exponential Equations (Scientific Notation)
Connecting Fractions, Decimals and Percents with a Calculator
Cramer’s Rule: Calculating a 2X2 Determinant With a Spreadsheet
Binomial Probability Distribution: Mean, Standard Deviation and Tables