Many students cruise along just fine in math — until they hit fractions:
National tests show nearly half of eighth-graders aren’t able to put three fractions in order by size.
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Knowing how to place fractions on a number line in third grade is a better predictor of kids’ fourth-grade fraction skills than calculation ability, working memory or the ability to pay attention, according to a recent study of 357 children headed by Nancy Jordan, an education professor at the University of Delaware, Newark’s Center for Improving Learning of Fractions. The effect continues at least through fifth grade, based on recent research, Dr. Jordan says.
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A child’s knowledge of fractions in fifth grade predicts performance in high-school math classes, even after controlling for IQ, reading achievement, working memory, family income and education, and knowledge of whole numbers, according to a 2012 study led by Bob Siegler, a professor of cognitive psychology at Carnegie Mellon University.
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“If you don’t understand fractions, it’s literally impossible for you to understand algebra, geometry, physics, statistics, chemistry,” Dr. Siegler says. “It closes a lot of doors for children.”