Steph Zech graduated from high school with an admirable academic record. She especially loves chemistry, writing and literature. However, when it comes to math, Steph has struggled a lot. At age 17, she still counts on her fingers to add 3 and 5. She did recently figure out if something costs 75 cents, the change from a dollar should be 25 cents. But when asked what the change would be if the price were 70 cents, she considered for a long time before venturing, “15 cents?”
There are many reasons for a student to be bad at math, including poor learning environments, attention disorders and anxiety. But Steph’s struggle is a typical example of a specific math disability known as “developmental dyscalculia (发展性计算障碍).” “A lot of people say ‘I’m not good at math’ because they couldn’t handle pre-calculus (微积分),” says cognitive neuroscientist (认知神经学家) Edward Hubbard of the University of Wisconsin-Madison. “People with dyscalculia struggle to tell you whether seven is more than five.”
Although dyscalculia, which affects about six percent of people, is as common as the reading disorder dyslexia (阅读障碍), it is far less well-understood. According to one analysis, studies on reading disabilities outnumber those that look at math deficits 14 to 1. One reason for the difference may be the belief that the ability to read and write is more important than the skill to do basic calculations.
尽管计算障碍影响了大约6%的人群，与阅读障碍综合征一样普遍，但它却远没有后者那么广为人知。 根据一项分析显示, 针对阅读障碍的研究大约是对于数学障碍研究的14倍。对于这种差异，其中一个原因可能是人们普遍认为读写能力要比基础运算能力来的重要。
Now thanks to advances in brain imaging (脑显像) techniques, new insights into the disorder have begun to emerge. Researchers have tracked dyscalculia to a fold (褶层) in the back of the brain. This area plays an important role in the development of the number sense, an intuitive (直观的) understanding of how numbers work. Studies show that even babies have a basic sense of numbers, but some are born with number blindness, which causes trouble connecting numbers to the real world.