Why does my child mix up 6×8 and 7×8?

Some times table facts are hard not because they're difficult to understand, but because they closely resemble other facts. This distinction matters for how you practise — and how you help.

What the research says

Dotan and Zviran-Ginat’s 2022 study examined specifically what makes certain times table facts hard to learn. Their finding: difficulty often comes not from complexity but from similarity to neighbouring facts. Facts with close answers — like 6×8=48 and 7×8=56 — create interference in memory, where one fact competes with another during retrieval.

In their study, first-grade children who practised dissimilar facts together in the same week learned better than those who practised similar facts together — because similar facts actively interfere with each other’s consolidation in memory. This interference effect persisted seven weeks after training ended, suggesting it operates on long-term memory directly.

A 2026 study by Eaves, Gilmore and Cragg looked directly at cognitive interference in multiplication fact learning and reached a compatible conclusion: children who struggle to suppress competing, similar-looking facts show more errors and slower recall on confusable pairs specifically — not on multiplication facts in general. This points to interference control, not weaker maths knowledge, as the driver.

What this means in practice

If your child reliably confuses certain pairs, that confusion is predictable and targetable. Standard practice treats all facts as equally independent — but some facts need to be distinguished from their neighbours explicitly.

Try this

• Identify the specific pairs your child confuses — they’re usually consistent, not random.
• Practise those pairs in direct contrast: ask 6×8, confirm the answer, then immediately ask 7×8 and compare.
• Don’t just increase overall practice on a confused fact — that often reinforces the wrong answer. Targeted contrast practice is more effective.

Last reviewed: 2026-08-01