What is interleaving and why does it matter for times tables?

Interleaving is one of the most counterintuitive findings in educational psychology: mixing up practice feels harder and produces worse results during practice — but significantly better results when tested later. Understanding why changes how you set up practice at home.

What the research says

Interleaving — mixing questions from different tables rather than drilling one at a time — is one of the most consistently replicated findings in educational psychology. A randomized controlled trial with seventh-grade students (Rohrer, Dedrick & Stershic, 2015) found scores of 61% for interleaved practice versus 38% for blocked practice one month after learning. The effect persists across age groups and subjects.

Dotan and Zviran-Ginat’s work specifically on times tables explains the mechanism: drilling one table at a time allows children to use sequential cues rather than retrieving facts individually. Interleaving removes those cues and forces genuine retrieval.

What this means in practice

Interleaved practice feels harder than blocked practice — children perform worse during it than during single-table drilling. This can feel discouraging. But the research is clear: the difficulty is the mechanism, not a side effect. Better performance during practice is not the same as better retention after practice.

Try this

• Always include facts from multiple tables in every session, even when focusing on a new table.
• Reassure your child that feeling unsure is part of the process — it means the memory is being genuinely tested.
• Don’t interpret slower in-session performance as a sign that interleaving isn’t working.

TabTabTab trains recall, not understanding. Building the concept of multiplication — arrays, repeated addition, commutativity — is classroom work, and it comes first.

Last reviewed: 2026-08-01