Notes from Tonle
Longer pieces, on the things worth writing down.
Essays about money, the small calculations that quietly shape big decisions, and the tools we build around them. Published when there is something to say.
Latest
How to Calculate Discounts: A Complete Guide to Percentage Off, Buy One Get One, and Stacked Savings
Master discount calculations with practical examples — from simple percentage-offs to stacked deals and BOGO offers. Learn the math that saves you real money.
Finance9 minRead the essay
Earlier
2026
Looking for something more reference-shaped? The guides library covers the same topics in a different format: organized by category, paired with the relevant calculator, written to be returned to.