Why does my child keep forgetting times tables?

Forgetting times tables is not a failure of effort or intelligence. It's a predictable consequence of how they're stored in the brain — and how most practice systems fail to account for it.

What the research says

Brain imaging studies by Dehaene & Cohen (1997) and Dehaene et al. (1999) show that times tables are stored in the language areas of the brain, not the mathematical ones. They are verbal memories, functionally similar to song lyrics or a familiar poem. Like any verbal memory, they require periodic retrieval to remain accessible. Without it, they fade.

This explains a pattern parents frequently notice: a child seems to “know” a table one week and forgets it the next. They haven’t lost a mathematical understanding — they’ve lost access to a memory that wasn’t practised enough to stick.

A 2019 study confirmed this pattern in children specifically: times tables that were not regularly retrieved showed measurable decay, regardless of how well they had been learned initially.

What this means in practice

Forgetting is not failure — it’s biology. The solution is building a practice system that revisits facts before they fade, rather than re-teaching from scratch each time.

Try this

• Don’t wait until a child has forgotten a table to revisit it. Retrieval practice works best just before forgetting — not after.
• Mix older, “learned” tables into daily practice alongside newer ones. Assuming a table is permanent is the most common cause of forgetting.
• If your child forgets frequently, increase retrieval frequency rather than increasing session length.

Last reviewed: 2026-08-01