A set of guidelines adopted by 45 states this year may turn children into "little mathematicians" who don't know how to do actual math. A few weeks ago, I wrote an article for TheAtlantic.com ...

People on TikTok are stunned that 29 multiplied by 3 is 87. Number values can be very psychological, "sounding" one way while being another. Division rules and common core principles can help unwire ...