Schools Matter and Mass: Exploring Science at St. Lawrence O’Toole by Gary Kopycinski on October 7, 2011 Gary Kopycinski Author More in Schools: Amauree Williams Caps Historic Southland Career with Three State Championships June 3, 2026 Mobile Museums of Tolerance Visits Park Forest June 3, 2026 Mia Narciso ’26 Wins IHSA State Championship in Original Oratory, Makes School History May 22, 2026 (Photo supplied) Matteson, IL-(ENEWSPF)- 4th and 5th grade students have been studying matter and mass, the school reports. Students investigated and conducted experiments. Here students used a balance to understand mass and density.