Yet there is a significant gap in achievement in math performance between low - income and higher - income children. (theounce.org)
If student math performance didn't improve, teachers had to sign a contract promising to return some or all of the money. (educationnext.org)
So the second assumption must be that «poverty» has a bigger impact on math performance for fifteen - year - olds than for younger students. (educationnext.org)