For the children who learn at their own pace,
and the families who sit beside them.
No signup. No tracking. No telemetry. No analytics.
The only time Cardinal connects to the internet is to check for updates — and only if you say yes.
Your child's work stays on your Mac.
Cardinal walks a child from sorting and one-to-one correspondence through addition with carry-over, long division, fractions with unlike denominators, decimals, and reading the clock. Every concept gets its own visual treatment. Every chapter has a playback transport so it can be watched as slowly as needed, scrubbed back, or paused.
Sorting, one-to-one, more & less, patterns, shapes, symmetry.
Subitising, counting, the number line, ordinal numbers, recognition.
Teen numbers, decade names, place value, comparing, ordering.
Number bonds, doubles, near doubles, halves, even & odd.
Addition, take-away, find-the-difference, fact families.
Make-10 strategy, carry-over, borrow, subtraction across zero.
Skip counting, arrays, every table 0–10, long multiplication, long division.
Halves and thirds, equivalent fractions, adding & subtracting fractions (same and unlike denominators), fraction multiplication, decimal arithmetic, × 10 / × 100 / × 1000, the analog clock, coins, perimeter, area.
The dots will wait for you.
— Cardinal's promise to the child
No timers. No streaks. No surprise sounds. No wrong-answer buzzers. Errorless throughout — the dot returns home if it isn't dropped where it should be. The same activity done forty times in a row is a feature.
Counting, addition, subtraction, number bonds, the number line, the analog clock — all interactive. Drag, tap, drop. Cardinal speaks the number aloud as the child interacts.
Carry-over isn't a procedure to memorise; it's ten ones bundling into a new ten-rod, with the carried "1" appearing the moment the bundle happens. Long division shares dots into piles physically. Subtraction across zero un-bundles a hundred into ten tens, then one of those into ten ones.
Every chapter ships with a per-chapter accessibility audit: VoiceOver summary, Switch Control path, Voice Control target names, Dynamic Type behaviour, Reduce Motion behaviour, target-size floor. The audit is a verifiable artifact in the codebase, source-scanned on every build. "We care about accessibility" is the cheapest claim software makes; Cardinal turns it into a contract.
Fractions and decimals use pure integer arithmetic under the hood. The classic 0.1 + 0.2 = 0.3 stays 0.3 — not the 0.30000000000000004 that calculators show. Kids see what they expect.
No signup. No data leaves your Mac. Pricing decision lands before v1.0 launches; the closed-beta build is free for participating families.
Cardinal-latest.dmg when it lands.Cardinal.app onto the Applications shortcut.
That's it. Cardinal is signed with an Apple Developer ID and notarised by Apple — macOS opens it directly with no warnings. If you have an older CardinalDemo.app in /Applications from v0.9.3 or earlier, you can drag it to the Trash; this is the same app, renamed.
Cardinal is free and one person built it. The only way it gets better is if you tell me what worked, what didn't, and what your child needs that isn't there yet.
Send feedback on GitHub · Join the discussion · Private report
Issue templates have built-in privacy gates — no child names, photos, or voices required (or wanted). Read the full feedback guide for the channel breakdown, or SECURITY.md for the private-disclosure path.