There is no such thing as common core math. The common core only specifies skill goals for students. How those skills are taught or in this case the method for

There is no such thing as common core math. The common core only specifies skill goals for students. How those skills are taught or in this case the method for solving math problems are not part of the common core. It is up to each school district to implement curriculum which teaches the common core goals. Most school districts have abdicated this responsibility to publishers and purchase curriculum. It is this purchased curriculum which teaches math in a manner which some parents object to, so their real issue should be with their local school district and the publisher.