Rachel Buzzini, 11, and Ryan Hause, 11, Liberty Valley fifth grade students, put on the finishing pieces to their groups K-Nex structure for the CSIU's K-Nex STEM Challenge on Tuesday in Milton.

Liberty Valley fifth grade student Allie Focht, 11, snaps together part of her team's K-Nex project during the CSIU's K-Nex STEM Challenge on Tuesday in Milton.

Liberty Valley fourth grade students Amelia Smith, 10, left, and Gianna Feldman, work together on their team's K-Nex project during the CSIU's K-Nex STEM Challenge on Tuesday in Milton.

Danville fifth grade student Allie Focht snaps together a K-Nex piece as she helps assemble her teams project on Tuesday at the CSIU in Milton for their K-Nex STEM Challenge.

Warrior Run fifth grade students Abby Evans, 10, left, Peyton Mehan, 10, and Cassie Herman, 10, work on their Seed Vault K-Nex project during Tuesday's CSIU K-Nex STEM Challenge in Milton.

Shikellamy fifth grade students Reagan Wiest, 11, focuses intently on putting a piece in place on her team's K-Nex project during the CSIU's K-Nex STEM Challenge on Tuesday morning in Milton.

Midd-West fifth grade students Miles Aurand, 10, left, and Tyler Long, 11, put together part of their teams K-Nex project for the CSIU's K-Nex STEM Challenge in Milton on Tuesday morning.

Fourth grade students from Shikellamy, Blaire Balestrini, 10, left, and Jade Weldy, 10, help put together their team's K-Nex project during Tuesday's CSIU K-Nex STEM Challenge in Milton.