On his website andertoons.com, illustrator Mark Anderson has a cartoon in which a boy is handing his teacher an assignment. “To show how well I understand fractions,” he says, “I only did half of my ...

Math proficiency is an important predictor of educational attainment and life success. However, developing mathematical competency is challenging, and some content (e.g., fractions) can be enigmatic.

The authors report a novel survey that narrows the gap between information about teachers’ knowledge of fraction arithmetic provided, on the one hand, by measures practical to administer at scale and, ...