NUMBERCADE
Math practice
backed by science.
Targeted practice for the foundational skills that trip kids up most, from fractions to pre-algebra.
▶ Play freeCovering the core skills kids need most
Number fluency • Fractions & percents • Order of operations • Equations • Slope • Geometry • Roots & exponents • Probability
From the founder
The Math Cliff
Around fourth grade, math takes a sharp turn, from concrete arithmetic to abstract ideas like fractions and probability. Standard curriculums are forced to move so fast that kids get rushed past these concepts before they truly master them. This is exactly when so many students lose their confidence and fall off the "math cliff." As a parent, I watched it happen.
As a PhD economist who spent years evaluating the rigor of education and labor policy research, I knew it did not have to be this way. There are decades of solid research on how kids actually learn math best, but it is buried under a mountain of noise. I built Numbercade to be the bridge: a science-backed, genuinely engaging tool that helps kids lock in the foundations, build confidence, and lay the groundwork for future success in STEM.
Dara, founder
Not worksheets. Not drill apps.
Cognitive science and behavioral economics,
applied to where kids actually get stuck.
Every game targets a core skill.
Fluency, fractions, equations, slope, geometry, exponents, probability. Start anywhere, play in any order, and jump back whenever something wobbles.
Grades 4 to 8. Free. No account needed to play.
Get started
Three steps. That's it.
The whole arcade is free.
No account · No paywall · No ads · No catch
Runs in your browser. No app to download. No credit card to enter. Just pick a game and play.
▶ Play freeYes, really. All eight games, every world, no ads, no paywall, no in-app purchases, and nothing to buy. No trial, no locked preview, nothing that expires.
No, and it's not trying to be. School (or your homeschool curriculum) covers the waterfront. Numbercade is targeted reinforcement for the eight skill areas where kids most often fall off the cliff: number fluency and negative numbers, equations, fractions/ratios/percents, order of operations, linear equations and slope, geometry, roots and exponents, and probability. Think of it as the climbing gym, not the mountain.
It helps with the part of test prep that transfers. The eight skill areas the games teach are the underlying concepts tested by admissions tests such as the ISEE and SSAT, and many practice items were modeled on the kinds of questions those tests actually ask. But Numbercade is not a test-prep product, and we are not affiliated with or endorsed by any test maker. The emphasis is understanding math concepts through methods grounded in rigorous research. A kid who genuinely understands slope, fractions, and probability walks into any test with the one thing a cram course can't shortcut. And if you are specifically prepping for the ISEE, that is a different job: we build a tool for exactly that, with real ISEE-style practice at ISEE Coach.
It's fifteen minutes of screen time with a job. Sessions are short by design, there's no infinite scroll, no autoplay, and no mechanic engineered to keep kids on past the lesson. The game literally tells kids to grab scratch paper. When the session's done, it's done.
The sweet spot is grades 4 to 7 (roughly ages 9 to 12). A strong third grader can start with the earlier worlds; an eighth grader shoring up algebra basics won't feel babied. The games never mention grade levels, so nobody feels behind.
Any modern browser: laptop, Chromebook, tablet, or phone. Nothing to install, nothing to update, no app store account. If it can load a webpage, it can run the arcade.
We designed for compliance by collecting almost nothing: one parent email for the account, kid profiles that are just a nickname and an emoji. No ads, no trackers, no data sales, and game progress lives on your device. Parents create and control all profiles.
Fair question, because that phrase can mean two different things. Meaning one: the product itself was tested in studies. Meaning two: the product was designed from practices that were tested. Most companies blur the two; we think you deserve to know which one you're buying. Numbercade is meaning two: the games were designed around findings from randomized trials and the Department of Education's practice guides, and each game includes a "The Research" page listing which mechanic implements which recommendation, with citations. In the federal ESSA evidence-tier system, that makes us Tier 4, Demonstrates a Rationale: a research-anchored design plus a public plan to study our own effects. It does not mean this product itself has been through a trial. We'd love the opportunity to collaborate and test the impact of the product in an RCT.
Not yet. It's on the list. Teachers who want to pilot it anyway: email us, we like you.