Children's arithmetic skills do not transfer between applied and academic mathematics

A paper in “Nature” shows the importance of experience in developing mental skills. The researchers examined the ability of Indian adolescents to do complex multi-step arithmetic in practical problems (in a market) vs. abstract problems (as equations).

Children who worked in a market were much better than non-working children at performing arithmetic when it was presented as a transaction. For the abstract problems, the non-working children performed better.

Moreover, there were differences in strategies. Children who did not work in markets were more likely to use paper and pencil for all types of problems, while children working in markets were often used addition, subtraction, and rounding to simplify multiplication and division. But both groups used this aid inefficiently. Often multiplication problems were decomposed into repeated addition problems (as in this example). Neither group is actually good at math by Western standards for children their age (most 11 to 15, but max = 17).

The result still stands, though, that experience in a market led to large numbers of children picking up algorithms for conducting transactions quickly with accuracy that is almost always “good enough” for their culture and context. This requires an impressive level of working memory for their age and education level.

There is a caveat that the authors mention, but don’t explore. An answer was marked as “correct” if it incorporated rounding either in the final answer or in preliminary steps, because this is a common practice in markets in India. Because the abstract problems were presented as equations, the children likely did not know that responding to 34 × 8 with an answer of 270, 275, or 280 (instead of the exact answer of 272). But in a market situation, these answers were considered “correct” and recorded by the researchers as such. The massive difference in performance in market-based problems may be mostly a result of the working children to rely heavily on rounding. So, this study does reveal a lot about the impact of different experiences on what psychologists call “number sense,” but not as much about exact arithmetic skills.

This study has important implications for intelligence. First, as Timothy Bates already pointed out, transferring learned skills from one context to another does not come easily or naturally. As a problem became less tied to the market context, the working children struggled more. Second, education builds cognitive skills, but turning those into abstract reasoning skills is much harder. This matches what the g theorists have been saying about how specific skills are trainable, but that general intelligence is difficult to raise.

The study is worth reading in full. It has no paywall.

Link to study: Children’s arithmetic skills do not transfer between applied and academic mathematics | Nature
Posted from X: https://x.com/RiotIQ/status/1935385971001884690?s=20

This is fascinating, it basically shows that “intelligence” isn’t some abstract thing floating in your brain, it’s deeply tied to context and experience. Kids who worked in markets crushed the practical math because they’d done it thousands of times, but couldn’t transfer those skills to abstract equations. It’s like they developed domain-specific expertise rather than general mathematical reasoning. Really challenges the idea that you can just “train” g through practice.

The rounding caveat is huge though! If market kids are getting credit for answers like 270 when the real answer is 272, but school kids have to be exact, that’s not a fair comparison. It sounds like the market kids developed a useful practical skill (fast approximate math) but not true arithmetic mastery. The fact that they used repeated addition instead of multiplication shows they never learned efficient algorithms, they just got really good at one specific context through sheer repetition.

@NickFR I agree, the rounding is a major point of context. But isn’t the whole point that ‘fairness’ is irrelevant when comparing skills learned in completely different domains? The study showed neither group could easily jump into the other’s territory. If the goal is practical competence (getting the right change quickly), then 270 is the right answer in their context. The real question is: Does knowing the exact answer of 272 matter more than knowing the useful answer of 270 in real life? :thinking:

@JuliaB Absolutely! It strongly supports the idea that while specific skills (domain-specific expertise) can be honed dramatically through repetition, that doesn’t automatically boost your general fluid intelligence. The market kids demonstrated incredible crystallized intelligence for transactions, but that knowledge didn’t ‘leak’ into abstract reasoning. It really backs up the g theorists who say true general intelligence is hard to raise.

I think it cuts both ways, though. The school kids also bombed at transferring their skills. Only a little of them could solve market problems that over a third of working kids got right. Maybe the real issue is that learning math in just one context creates knowledge that doesn’t travel well.

The study also exposed a curriculum design problem anyway. Neither group is learning math in a way that builds both practical fluency and the ability to think abstractly. Maybe it would be better if people actually tried to bridge both worlds from the start instead of treating them as separate things.

Aren’t we too quick to write off approximate math as inferior? In the market kids’ actual environment, their approach is smarter since they’ve figured out when precision matters and when it doesn’t, and they’ve optimized for the speed-accuracy tradeoff that actually matters in real transactions. Western math tends to drill precision without ever teaching the judgment call of when you actually need to be that precise. That should be a skill too, right?