Counter: Math
Make sums X+Y=Z
About this trainer
Counter: Math is a timed mental-arithmetic drill. The screen shows a quick chain of operations or a single problem, and your job is to compute the answer in your head and enter it before the clock runs out, then immediately move on to the next one.
What it develops
It trains working memory and processing speed for numbers — holding intermediate results in mind, applying the right operation, and retrieving basic number facts fast and accurately under time pressure.
History
Mental calculation is one of the oldest learned skills, taught for centuries through the abacus and soroban and through everyday market and trade arithmetic. Speed-calculation systems such as the Japanese mental abacus (and its flash anzan offshoot), Vedic mathematics and the Trachtenberg method later formalised tricks for doing it faster, and timed arithmetic drills like this one are the digital descendant of that long tradition.
Who created it — and when
There is no single inventor — mental arithmetic is a generic exercise that belongs to the broad tradition of abacus and school-arithmetic training. Named systems exist around it: the Trachtenberg method was devised by Jakow Trachtenberg in the mid-20th century, and Vedic mathematics was popularised by Bharati Krishna Tirtha in a book published in 1965, but the underlying skill predates all of them.
How to train
Don't sub-vocalise digit by digit; learn to chunk and round (treat 48 as 50 minus 2). Memorise the building blocks — small multiplication tables, complements to 10 and 100 — so retrieval is automatic. Push for a comfortable speed first, then trim it; accuracy under mild time pressure beats reckless guessing.
How long to practise
Short, frequent sessions work best: 5 to 10 minutes a day beats one long weekly grind. Stop when accuracy starts to slip, since fatigue trains sloppy habits rather than fluency.
Evidence base
The solid finding is the obvious one — practise mental arithmetic and you get measurably faster and more accurate at mental arithmetic, and working memory is reliably correlated with arithmetic skill. The bigger claims are weaker: broad transfer to general intelligence or unrelated everyday tasks is largely unproven, brain-training games have repeatedly failed to show far transfer in well-controlled studies, and even mental-abacus research disagrees on whether it lifts working memory itself. Treat any '+IQ' promise with caution.
Recommendations
Keep the difficulty just past comfortable — problems you solve in a few seconds with effort — and practise daily in short bursts rather than rare marathons.
FAQ
Will this make me smarter or raise my IQ?
Realistically, no. You will get noticeably better and faster at mental arithmetic, but there is little reliable evidence that it boosts general intelligence or unrelated skills, so we don't promise that.
Is it cheating to round numbers or use shortcuts?
Not at all — chunking, rounding and learned tricks like complements are exactly how fast mental calculators work. The goal is the correct answer quickly, not a particular method.
How is this different from doing math on paper or a calculator?
Paper and calculators offload the storage; here you have to hold the numbers and partial results in your head, which is what makes it a working-memory and speed exercise rather than just an arithmetic test.
Variants
Variants change the operations (addition and subtraction only, or full multiplication and division), the length of the chain, the number ranges, and whether the clock is fixed or speeds up as you go. Related disciplines include soroban-based mental abacus, flash anzan and rapid times-table drills.