📚 Elementary school Mathematics · free & open source

Luna's Math Quest

A free, open-source elementary-school math program for children ages 5–11 — from a child’s very first counting in Kindergarten through fractions, decimals, and long division by Grade 5. Built for kids, and for the parents and teachers guiding them.

Kindergarten – Grade 5ages 5–11 10worlds 50activities 41guided lessons Freeno ads, ever

This whole course is open. It is plain data — a single math.course.yml composing the engine's building blocks. Read it, learn from it, or fork it to build your own.

⟨/⟩ View math.course.yml ↗ Engine primitives →

How it teaches

The same research-backed approach runs through every lesson.

See it before you symbolise it

Every skill starts with a concrete picture — counters, ten-frames, base-ten blocks, number lines — before any digits or signs. Children build the idea first (the concrete → pictorial → abstract progression research keeps pointing back to).

One idea per stop

Each station teaches a single concept and only moves on once it lands, so understanding compounds instead of gaps piling up.

Remember it, don’t cram it

A spaced-review deck quietly brings earlier skills back at the right moment, turning practice into long-term memory.

A patient, friendly guide

Luna the owl narrates each step in short, warm sentences — written to be read aloud for pre-readers.

What your child learns — the worlds

Each world is a themed stage that builds on the last. Open one to see every activity broken down step by step, with the pedagogy and the open config.

🌼

Number Meadow

World 1

Counting, comparing, number bonds, and adding & subtracting within 20 — the bedrock of number sense.

🔢 Counting⚖️ Bigger or Smaller🤝 Friends of 10➕ Adding to 20➖ Taking Away
🏔️

Place Value Peaks

World 2

Tens, ones and hundreds, skip-counting, and odd vs. even — reading and building bigger numbers.

🧱 Tens & Ones💯 Hundreds🔣 Two-Digit + and −🦘 Skip Counting🎭 Even or Odd
🏜️

Carry Canyon

World 3

Column addition and subtraction with carrying and borrowing, rounding, and first story problems.

➕ Long Addition➖ Long Subtraction🎯 Rounding📖 Story Problems
🛤️

Times Table Trail

World 4

Multiplication as equal groups and arrays, the times tables, and the matching division facts.

🟪 Groups & Arrays✌️ Tables 2, 5, 10🎲 Tables 3, 4, 6🎪 Tables 7, 8, 9➗ Division Facts
⛰️

Multiplication Mountain

World 5

Long multiplication and long division, plus multi-step puzzles.

✖️ Multiply ×1 Digit🧮 Multiply ×2 Digits➗ Long Division🧩 Multi-Step Puzzles
🌳

Fraction Forest

World 6

What a fraction is, equivalent fractions, comparing, and adding fractions.

🍕 What is a Fraction?🪞 Equivalent Fractions⚖️ Compare Fractions➕ Add Alike Fractions🔀 Mixed Denominators🥪 Mixed Numbers✖️ Fraction × Whole

Decimal Docks

World 7

Decimal place value, comparing, add/subtract, and the link between fractions and decimals.

🔬 Decimal Places⚖️ Compare Decimals➕ Add & Subtract🚀 × and ÷ by 10, 100✖️ Decimal × Whole🔁 Fractions ↔ Decimals
📏

Measure Marsh

World 8

Money and change, telling and elapsed time, length and weight, and unit conversions.

💰 Money & Change🕒 Telling Time⏳ Elapsed Time⚖️ Length & Weight🔁 Unit Conversions
🌌

Geometry Galaxy

World 9

Shapes and symmetry, angles, perimeter, area, and volume.

🔷 Name the Shapes🦋 Symmetry📐 Angles🧵 Perimeter🟩 Area📦 Volume
🦁

Word Problem Wilds

World 10

Putting it all together — one- and two-step word problems and a grand challenge.

📗 One-Step Stories📘 Two-Step Stories🏆 Grand Challenge

Questions parents & teachers ask

Is Luna’s Math Quest free?

Yes — every lesson is completely free to play, with no ads.

What ages and grades is it for?

Elementary school: Kindergarten through Grade 5, roughly ages 5–11.

Is it really open source?

Yes. The whole course is published as an open math.course.yml you can read, learn from, or fork on GitHub — that openness is the point.

Do we need to install anything?

No. It runs in any web browser, on a computer or tablet.

What math does it cover?

Counting and place value, addition and subtraction, multiplication and division, fractions, decimals, measurement, geometry, and word problems.

Update Log

Recent changes to this open course — straight from its commit history.

2026-06-13 · Update

Full history on GitHub →

Want to build a quest like this? Anyone can. Courses are content, not code — compose the engine primitives, supply the words, and open a pull request.

How to create a course →