In 2012 the New York State Education Department contracted with the organization that would become Great Minds to create an open educational resource (OER) math program for K–12 educators. We wrote EngageNY Math, and over time we developed that program into Eureka Math. The original OER curriculum is available on the EngageNY and Great Minds sites for free, and it has been downloaded over 13 million times by users in all 50 states, making Eureka Math the most widely used K–5 math program in the country.