STEM
RatioRealm
Master ratios, proportions, and percentages through real-world simulation contexts — recipe scaling in kitchens, blueprint ratios in construction, and map scales in cartography — with visual models like the double number line. Ages 10-14.
▶ Play it nowBuilt for sittings of about 20 minutes on the screen. That is our design budget, not a measurement.
Meet your mentor
Every Spark & Anvil app has a friendly mentor character that demonstrates, asks, and patiently scaffolds learning. On-device AI personalizes the mentor's responses to your kid's progress — never connecting to a server, never collecting data.
Mentored by Scale
#29B6F6 RatioRealm makes ratios something you can see: scale a recipe on a double number line, read a map or a blueprint to scale, judge which mix is stronger, and work rates, proportions and percents.
Characters who teach
Meet the cast
RatioRealm's characters each teach one idea about ratios. Pair says "for every A, there are B," Scale doubles a recipe the right way, Unit finds the amount per one, Cross solves proportions, and Centa works with percents. Crux, Keel, Portion, Splay, and Warp cover direct and inverse proportion, the constant that links two amounts, sharing fairly by a ratio, scale drawings, and part-to-part versus part-to-whole. Scale is the mentor who guides them.
Pair the Ratio-Speaker
Simple ratios (a:b) — the foundational "for every A, there are B" pattern
Read chapter →
Scale the Doubler
Equivalent ratios (scaling both parts by the same factor; recipe-doubling primitive)
Read chapter →
Unit the Per-One-Counter
Rates and unit rates (the per-one normalization that lets us compare different rates)
Read chapter →
Cross the Proportion-Solver
Proportions and cross-multiplication (the canonical "if a/b = c/d then ad = bc" mechanic)
Read chapter →
Centa the Percent-Translator
Percentages — the per-hundred special case + percent change
Read chapter →
Crux the Two-Directions
Direct versus inverse proportion (when one goes up, the other goes up — or down)
Read chapter →
Keel the Constant-Keeper
The constant of proportionality (the fixed number that links the two quantities)
Read chapter →
Portion the Fair-Divider
Sharing a quantity in a given ratio (splitting fairly by parts)
Read chapter →
Splay the Scale-Keeper
Scale factor (scale drawings, maps, and models)
Read chapter →
Warp the Part-and-Whole Namer
Part-to-part versus part-to-whole ratios (naming what is compared to what)
Read chapter →
Browse all chapters → · What's distributed-narrative methodology? →
What's inside
What Even Is a Ratio?
A ratio compares two numbers. Like if you have 2 cats and 3 dogs, the ratio of cats to dogs is 2 : 3. Ratios are everywhere -- in recipes, maps, sports stat
Starting the App
When you open RatioRealm, you'll see the Main Menu. Here's what you can do:
Choosing a Context
Tap Choose a Context to pick what kind of problems you want to solve:
Solving Problems
After you pick a context (or tap Quick Practice), you'll see a math problem. Here's how it works:
Mentored by Scale — on-device AI, no data leaves the device.
How RatioRealm handles your kid's data
- ✅ All progress, settings, and AI-generated content stays on the device
- ✅ No analytics, no tracking, no third-party SDKs
- ✅ Free — no ads, no in-app purchases
- ✅ No personal information collected from children — in line with COPPA (updated by the 2026 FTC amendments)
- ✅ No chat with strangers — play-together rooms use a short code and preset emotes, never typed messages
RatioRealm runs on ForgeKit — the open-source Swift Package Manager framework that powers every Spark & Anvil app. ForgeKit ensures consistent accessibility, COPPA compliance, and design language across the portfolio, so your kid's progress and preferences feel coherent across every app they touch.
Coming to the App Store
RatioRealm is in active development. Email us to hear when it ships — no marketing, no spam, just a one-shot launch announcement.
Email me at launch
