More than one right answer, more than one right method. While those tasks make sense for 5th graders, kindergartners—and even preschoolers—can learn math through problem solving, Boaler said.

Shanaya Amernath is solving a worksheet of math problems. Some of the calculations involve several digits, ... I'm not too sure it's about patterns, it's more like an aptitude," she said.

To be sure, a problem-based or open-ended approach to teaching math is often pitted against more traditional, procedural methods—think of the math worksheets full of equations without context.