Why "fair shares" comes before fractions
Before a child can understand one-fourth, they have to understand that fourths must be EQUAL — and research shows many students never get that memo. The deepest fraction misconceptions trace back to accepting any split as a fraction: shade "1 of 4 parts" and call it a fourth, even when the parts are wildly different sizes. The Common Core roots fractions in equal partitioning for exactly this reason, and studies of children's thinking (notably Empson's work on equal sharing) show that fair-sharing problems — "share 3 brownies among 4 kids" — are how young children invent fractions for themselves, before any notation. This tool trains both halves of that foundation: a flash judgment of fair vs. not-fair parts, and sharing scenarios where the class watches equal cutting turn items-per-person into a fraction — including shares bigger than one whole, so a fraction never gets welded to "a piece of one thing."