It's not a memory problem, and it's not really about the summer holidays either. Here's what's actually going on.
25 August 2026 · 5 min read
Every September, teachers across the country spend the first few weeks reteaching things that were, on paper, covered and understood the previous July. It's easy to blame the six-week break, but the same forgetting happens over much shorter gaps too — a topic covered in October can feel half-forgotten by February if nothing brought it back in between.
The natural assumption is that once a child "gets" something, it's learned for good. In practice, understanding fades unless it's used. This isn't a flaw specific to any one child — it's simply how memory works for everybody, adults included. A skill practised once and never revisited weakens over time, even if it seemed completely secure the day it was taught.
The curriculum moves forward by design — fractions get taught, then the class moves to decimals, then percentages, then algebra. Each new topic gets weeks of focused attention, and the previous one quietly stops being practised at all. Without deliberately circling back, there's often no natural reason for a child to touch fractions again for months after the unit ends, which is exactly the condition under which forgetting happens fastest.
What looks like a concept disappearing is usually closer to a concept becoming hard to access rather than being gone entirely. Given a strong enough prompt — a worked example, a reminder of the method's name, the first step written out — most children recognise the idea again quickly. That's actually good news: it means bringing a "forgotten" skill back rarely takes as long as learning it the first time. The knowledge was there; it just hadn't been called on recently enough to stay easy to reach.
The research on this is fairly consistent, and the practical version is simple: short, spaced revisits beat one long session, and being asked to recall something beats being shown it again. Re-reading a worked example is far less effective than being handed a fresh question on the same skill a few weeks later and having to solve it without a prompt. That act of retrieval — pulling the method back out from memory rather than recognising it on the page — is what actually re-strengthens it.
Mixing topics also helps more than it seems like it should. A practice session that revisits fractions, place value and multiplication in the same sitting, rather than twenty questions on one topic in a row, forces a child to identify which method applies each time — which is closer to how maths gets used in real exam papers, and closer to what builds lasting recall.
If a child seems to have "forgotten" something they clearly understood a term ago, it's rarely a sign they never really learned it. It usually just means that skill hasn't been touched in a while and needs a short, deliberate revisit rather than reteaching from scratch. A few minutes of mixed, spaced practice across the topics already covered tends to do more for long-term retention than an equivalent amount of time spent purely on whatever's newest.
Grasp Maths doesn't treat a skill as finished the moment a child gets it right. It checks back on previously mastered skills at increasing intervals, mixed in with newer material, so understanding gets reinforced through spaced retrieval before it has the chance to fade.
Don't just practise more. Practise what matters next.
Try a free Grasp Maths practice session and see how spaced revisiting keeps old skills secure.