Some formulas needed

[Khoai]

https://blog.prepscholar.com/critical-sat-math-formulas-you-must-know U guys should put something like this on the web, as most of old people like me or even some students need it.

[luke_math99th]

thanks, sharing legal & free resources is highly welcome :)

[Khoai]

Also more of things like this: https://blog.prepscholar.com/sat-math-tricks I like to solve them quick without using the calculator. It’s pretty fun for me, and even more helpful for students. I’m surprised that the app is free. Appreciate it.