The classic workouts

What you do in the classic workouts

Three quick keypad workouts: Add & Subtract, Multiply & Divide, and I'm Feeling Clever, which mixes all four operations. Each round is 10, 20 or 50 sums against the clock (you choose in Settings), with a personal best to beat.

• Math Adapt AI quietly tunes each round: more of the kinds of sums that slow you down.
• When you are flying, Doc offers a step up in difficulty.

Doc explains

The science idea

Scientists also call this the testing effect. The surprising part is that a quiz is not only a way to check what you know: answering the question is itself a strong way to learn, and it beats simply going over the material again.¹

For arithmetic, the aim is fact fluency: knowing facts like 6 × 7 well enough that the answer arrives quickly and correctly. A brain scan study of high school seniors found that students whose brains leaned more on regions used for recalling number facts during simple sums tended to have higher math test scores. That is a correlation, not proof of cause and effect.²

A second idea sits inside I'm Feeling Clever: mixed practice, also called interleaving. Instead of ten of one kind of sum and then ten of another, the kinds are shuffled, so each time you first have to decide what kind of sum it is.³

What the research found

A meta-analysis of practice testing pooled many studies and found that practice tests helped learning more than restudying the material, and more than every other comparison the studies used. The size of the benefit varied with the kind of test and the learners.¹

Spreading short timed practice across the day helps too. In a classroom study of 48 third graders over 19 days, children who did one minute addition sprints spread through the day grew their fact fluency faster than classmates who did the same sprints back to back.⁴

Mixing problem types can pay off later. In a randomised trial across 54 seventh grade math classes, classes that practised with mixed sets scored 61% on a surprise test a month later, against 38% for classes that practised one type at a time.³ A meta-analysis of interleaving found a moderate benefit overall but a smaller one for math tasks, and for some materials, such as word lists, practising one type at a time worked better.⁵

What about the clock? A review of time pressure, stress and math anxiety found only 19 relevant studies and not yet much evidence of clear links.⁶ In a study of 81 fourth and fifth graders, timed drills raised the number of digits answered correctly overall; children with high math anxiety scored lower in every condition, and the study did not find that timing hurt them more.⁷ In a small study of 36 mathematically gifted sixth graders, children with more math anxiety or perfectionism showed a smaller, not larger, gap between timed and untimed scores.⁸ So timed practice can build speed, some children find time pressure stressful, and the research has not settled how much the clock itself causes anxiety.

How the classic workouts use it

• Every sum is answered from memory on a keypad, with a live clock: retrieval practice under light time pressure, close to the timed sprints in the classroom study.⁴
• Rounds are short (10, 20 or 50 sums), so practice comes in small pieces rather than one long session.
• A wrong answer shakes and clears so you can try again, the third wrong shows the answer, and each wrong adds 5 seconds to your final time. Those are the app's own design values, not numbers from a study.
• Every first try is saved and feeds the memory model behind your Progress screen, so the same answer also decides which facts come back for review.
• I'm Feeling Clever picks each sum's operation at random from all four, so it usually changes from one sum to the next. That is close to interleaving, but random: two of the same kind can follow each other, unlike the carefully arranged sets in the trial.³

What this does and doesn’t mean