# 澳门金沙网页游戏:Word power

By Nell Boyce OUR brains can make rough mathematical calculations without language, but exact calculations need language skills, a new study suggests. The discovery may point to better ways of teaching maths. Scientists have long wondered to what extent language is required for maths. Despite their lack of language skills, even monkeys and five-month-old infants have some ability to understand numbers. They gape in surprise when they see someone put two dolls behind a screen and then raise the screen to reveal only one doll (“It all adds up”, New Scientist, 7 March 1998, p 42). Also, the brain centres that process numbers seem to be different for exact and approximate calculations. Some patients with strokes or brain damage have severe difficulty with language and exact calculations, while their ability to estimate remains intact. Elizabeth Spelke and Sanna Tsivkin of the Massachusetts Institute of Technology investigated the role of language in maths by enlisting eight adults who spoke Russian as their native language and were fluent in English. To mimic the process children go through as they learn maths, the researchers taught the subjects complex arithmetic and unfamiliar approximations. Some exercises were taught only in English, others in Russian. The teachers wrote numbers out as words rather than using Arabic numerals. Spelke and Tsivkin then tested the students by giving them problems to solve in both languages. When asked to make exact calculations (does 53 plus 68 equal 121 or 127?) the students took about a second longer to come up with the answer if the question was not asked in the language they had been taught in ( Science, vol 284, p 970). But there was no language-dependent time lag when they were asked to approximate (is 53 plus 68 closer to 120 or 150?). As part of the same study, Stanislas Dehaene and his colleagues at the French medical research organisation INSERM and Frédéric Joliot Hospital in Orsay looked at brain images of people doing calculations. Exact calculations increased the activity of speech-related areas of the brain’s left frontal lobe, while estimates increased activity in the left and right parietal lobes. These regions help control hand and finger movements and, perhaps, counting on fingers. “I was amazed that the association could be so sharp,” says Dehaene. The findings may have implications for maths teaching. “If a child begins learning arithmetic in one language, is there a cost if the language is switched later on?” asks Spelke. Dehaene adds that even if children have severe language problems, they could still develop their numeracy by concentrating on approximate calculations. Brian Butterworth at University College London, who studies how the brain handles mathematics, says the results are fascinating. However, he suspects the verbal and nonverbal parts of the brain don’t work alone, but interact in complex ways. People often break down exact mathematical tasks, for example, turning nine plus seven into ten plus six. “There would be big overlaps,