Numerals in news headlines act as an information-gateway signal, increasing engagement, perceived informativeness, and memory

People increasingly distrust news and engage with it irregularly. Can the presence of numbers in headlines encourage news engagement and, if so, why? We show that the presence (vs. absence) of at least one numeral (“3”) in tests of headlines increased click-throughs to associated articles by 3.6% at The Washington Post and 5.2% at Upworthy, after controlling for other engagement-related factors. A preregistered experiment (n=765) demonstrated causal effects: Participants selected headlines with numerals more than those with verbal labels (“several”) or similarly precise, logically identical written-out numbers (“three”), suggesting that numerals were not simply more precise. Participants also formed more positive impressions of numeric headlines and remembered their number-related and non-numeric information better. Font-fluency manipulations did not moderate number-type effects, although did increase numeric memory. We propose that the presence of numerals may act as a cognitive information-gateway signal influencing attention and encouraging engagement in noisy digital ecosystems.