Most educational apps say "science-based" and hope you won't ask. This page is for parents and teachers who do ask. FactForest is built on four of the most consistently replicated findings in a century of memory research — here is each one, what it says, and exactly how the forest uses it. Sources are at the bottom; please check them.
The intuitive way to learn is to look at material again and again. The research says something surprising: the act of pulling an answer out of memory strengthens that memory far more than re-reading it — even when the retrieval attempt fails. This "testing effect" is one of the most robust results in cognitive psychology, demonstrated across ages, subjects and decades of studies [1, 2].
Hermann Ebbinghaus mapped the "forgetting curve" in 1885: memories decay fast at first, then slower [3]. The counter-move is spaced repetition — reviewing at expanding intervals (a day, three days, a week...), each review landing just as the memory weakens. A major meta-analysis of 254 studies confirmed spaced practice reliably beats massed practice, across ages and materials [4]. It is why medical students memorise thousands of facts with spaced-repetition software.
Practising one times table in a block ("all the 7s") feels smooth and productive — and produces weaker long-term learning than mixing problems, because mixing forces the child to retrieve which answer fits, not just repeat a pattern. Studies in mathematics practice specifically show large gains for interleaved over blocked practice on delayed tests [5].
Working memory is small. A child who must work out 7×8 while solving a fraction problem is running two problems at once, and cognitive load theory shows the fraction learning suffers for it [6]. When number facts become automatic — retrieved instantly, without effort — working memory is freed for the actual mathematics. This is why England's Year 4 Multiplication Tables Check allows just six seconds per question: it is testing automaticity, not calculation [7].
The spacing research has a practical corollary: three five-minute sessions across a week beat one long weekend session — and a five-minute session before school is a routine families can actually keep. The day streak in the forest exists to protect that routine, not to pressure anyone: miss a day and nothing is lost but the streak number; the trees wait patiently (they just get a little thirsty).
FactForest will not make your child "love maths" overnight, and no app replaces a teacher, a parent's encouragement, or understanding why multiplication works — arrays, groups, and number sense belong to the classroom and the kitchen table. What the forest does is one job, on strong evidence: it makes the 144 facts automatic, so the interesting maths gets easier. And it does that job with no ads, no account, and no data about your child ever leaving your device.