Recent public debates have focused a spotlight on K-12 math pathways. But there’s been less attention paid to what math skills students need early in life, to set them up for elementary school in the first place.

For early learners, exposure to math concepts can be at the mercy of their family’s economic status or related factors like whether their parents are college-educated. That’s why one group of researchers asked what can be done to close the cognitive development distance that opens between children from high- and low-income families, which they argue is a watershed in equality of opportunity.

The resultant randomized controlled trial, “Boosting Parent-Child Math Engagement and Preschool Children’s Math Skills,” tried to hoist up the math skills of children ages 3 through 5 in Chicago. These 758 students — who were enrolled in Head Start programs or other publicly subsidized preschools — were from low-income families. Study participants were split into groups that received different educational materials. For some parents, researchers loaded up tablets with vetted apps designed to teach math skills, and then handed them to the families and walked away for six months, says Ariel Kalil, a professor at the University of Chicago Harris School of Public Policy and the director of the Center for Human Potential and Public Policy. Some parents received analog games designed to convey math skills, while others received a storybook. Researchers sent text reminders to some parents to use the materials they received.

The result? Some of it worked really well. There was no noted effect at the end of the original treatment, which lasted 12 weeks. But when researchers came back six months later, kids who had been using the apps saw math skills increase by 0.2 standard deviations, according to the report — an improvement bigger than students typically see after one year in a Head Start program. Groups that were given analog games and parental messaging saw improvements, too.

Another result: Girls got a bigger skills bump from the tablets than boys. That’s likely related to the fact that girls develop quicker in general, and can be able to self-regulate in younger years, Kalil speculates.