Chemistry Collective
Chem Collective: Stoichiometry Tutorials: Dimensional Analysis
Watch a short tutorial showing the conversion between the amount of a substance expressed in number of molecules to the amount of a substance expressed in moles of molecules, and then try some dimensional analysis practice problems.
University of Cambridge
University of Cambridge: Nrich: Making Cuboids
How many different cuboids can you make? Learn how and learn how to represent data with your results.