Mixing up your practice problems beats grinding one type at a time

Students who practiced math problems in shuffled order scored roughly double the students who drilled one problem type at a time, even though blocked practice felt easier in the moment. Interleaving forces you to keep choosing which method fits which problem — the skill a real test actually demands.

— Kelli Taylor and Doug Rohrer, The Effects of Interleaved Practice — Applied Cognitive Psychology, 2010