Scratch, developed by the MIT Media Lab, is a block-based visual programming language and online community targeted primarily at children.
Children can create their own interactive stories, games, and animations.
How Scratch Works
Math Olympiad course is designed to teach the major strategies of problem-solving, to foster mathematical creativity, and to stimulate enthusiasm and love for the types of problems that students encounter in competitive mathematics.
https://cty.jhu.edu/online/courses/mathematics
Drawing a Picture or Diagram
Using Deduction
Simplification
Finding a Pattern
Making an Organized List
Making a Table
Using Number Operations
Working Backwards
Basic Geometry
Estimation and Elimination