Schools Matter and Mass: Exploring Science at St. Lawrence O’Toole by Gary Kopycinski on October 7, 2011 Gary Kopycinski Author More in Schools: Save the date for The Prairie Party at theNate June 17, 2026 Governors State Has New Soccer Complex and New Men’s Coach June 17, 2026 Amauree Williams Caps Historic Southland Career with Three State Championships June 3, 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.