I loved math at a young age.
I figured it was a gift God wanted me to develop and share.
So, I earned several college degrees: one in mathematics and the others in electrical and computer engineering.
I worked in corporate America for 42 years, mostly focusing on software development and cybersecurity.
My end goal has always been to "retire" and teach math/STEM at a university.
Every semester, I tutor 6 to 12 students, mostly through Wyzant.
I've tutored students 6 days a week since 2009.
When I found myself writing notes and equations in my one-on-one tutoring lessons for the third time in a week, I thought, "Why don't I just put them in a cheat sheet?"
100+ cheat sheets later, here I am.
I add new cheat sheets often and update them frequently.
In addition to helping my students, these reference documents, or cheat sheets, help me remember what I learned and share this knowledge more effectively.
I share them freely, following the lead of two of my STEM heroes:
• Paul Dawkins, who shared all of his Paul's Online Notes for mathematics in 2003.
• Elon Musk, who shared all of his Tesla patents in 2014.
Each cheat sheet is published with both the original Microsoft Word document and the accompanying PDF document, allowing you to download and modify them as you see fit.
I hope you find them useful.
Harold Toomey
McKinney, TX
email
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Last updated 21 October 2026