When it comes to numbers, how you write them can shape what people believe. New research co-authored by Anand Kumar, professor of marketing at the University of South Florida, finds that consumers respond more positively to numbers written as digits, like “10 grams of protein”, than to the same information spelled out as “ten grams of protein.”
The study, published in the Journal of Consumer Research, draws on six controlled experiments, two real-world online ad campaigns and an analysis of tens of millions of online reviews. Across settings, messages using digits consistently sparked greater interest, stronger intentions to act and more favorable product evaluations.
Why? It’s not that people misunderstand number words. Instead, digits simply feel more “right.” Consumers expect numerical information to appear in numerical form. That intuitive fit boosts confidence in the message, even though the underlying information doesn’t change.
The effect is especially powerful when credibility is uncertain. For unfamiliar brands, new products or ambiguous public health messages, presenting numbers as digits can meaningfully improve how people respond.
For marketers, policymakers and organizations communicating data-driven claims, the takeaway is refreshingly practical. Small formatting choices can influence perception. When trust is still being built, writing “10” instead of “ten” may make a measurable difference.
Authors: Marisabel Romero, University of Tennessee; Adam W. Craig, University of Kentucky; Milica Mormann, Southern Methodist University; Anand Kumar, University of South Florida.