<p>Armstrong Elementary School is a California Distinguished School and a National Blue Ribbon School in North Diamond Bar serving 300 students. It is a part of the Pomona Unified School District.</p> <p>From 2009 to 2010, Armstrong's Academic Performance Index score rose 11 points from 848 to 859 (on a scale of 200-1000). Compared statewide, the school's API scores 8/10. Compared against a group of 100 similar schools, the score is 3/10.</p> <p>Its mascot is the Eagle.</p>