About Daon Opus
Daon Opus is a small independent math studio. We do two things: we write practical math articles that a real person can use, and we build free tools that let someone practise without an adult sitting next to them. Everything on this site comes from that one job.
Who is behind Daon Opus
Daon Opus is an independent math publisher. Everything here is published under the Daon Opus byline because Daon Opus is accountable for it.
We use AI tools to help with drafting and research, and we tell you that plainly because it changes how you should read the page. Nothing publishes without being worked through line by line, checked for its arithmetic and its reasoning, and rewritten wherever it does not hold up. Treat what you read here as a first draft that has been checked, not as an authority.
That includes correcting ourselves. If an article here is wrong, the email address below reaches us and it gets fixed.
How our articles are written
Every article is written to be used, not skimmed. Our rules are consistent, and they are the reason the library is 137 articles long rather than 1,350 shallow ones:
- One idea per article. If a topic has three ideas in it, it becomes three articles, each of which you can finish.
- At least 1,000 words. Enough to show the reasoning, the mistake, and the case where the rule stops working.
- Worked examples. Real numbers, shown step by step, not a formula with no demonstration.
- The mistakes families actually make. Most of our articles start from something that went wrong, not from a definition.
- Cross-linked. Articles link to each other and to our free apps, so you can go from an explanation straight to practice.
- No overlap. Before we write a new article we check the whole library, so we do not publish the same idea twice.
If a topic is outdated or a curriculum changes, we revise the article and the byline shows the date it was last updated. Corrections are welcome — send them through the contact page and they get fixed.
What is in the library
The articles are grouped into four sections, and the largest one is concepts, because that is where most real questions land:
- Concepts — 94 articles on the maths itself, from arithmetic through to geometry, probability and statistics
- Study skills — 22 articles on how to practise, remember and handle test anxiety
- Wellbeing — 17 articles on motivation, screen time and keeping a child going
- Standards — 4 articles on what the grade levels actually require
Recently published
- Codes and Ciphers: The Secret Math of Messages — why shifting every letter still leaves English's fingerprint showing
- Big Numbers: Millions, Billions, Trillions and Beyond — the prefixes are doing the arithmetic for you
- Distance = Rate x Time: The Formula That Moves the World — the formula your fuel gauge runs backwards
- Converting Units: When to Divide, When to Multiply — why a conversion factor is a fraction equal to 1
- Congruent vs Similar: The Same Shape or Just in Proportion — the real world has no such thing as exactly congruent
- Math and Screen Time: Finding a Healthy Balance — a one-device rule that survives a school night
Our products
The apps exist so that an article you just read has somewhere to go next. All of them are free and none of them require an account:
- G12345 — elementary school math tutor, grades 1–5
- G678 — middle school math tutor, grades 6–8
- G9101112 — high school math tutor, grades 9–12
- Math Q&A — community math help, where a question is answered by a person
- Practice topics — guided practice by topic, from counting through to algebra
- Playground — short maths mini-games
Contact
Reach us at sanopus@gmail.com. Bug reports, corrections, feature requests and disagreements about a maths claim are all welcome, and we reply to everything within one to three business days.