What if each student built a bit of the chain themselves and then you added all the bits together to create a 100 link long chain? How long might that chain be when it is finished? Great group/estimation project!
Beaded number rods for subtraction! Great visual for students with special needs. Adding concrete materials when performing simple operations, helps build number sense to ensure students are relating quantities to symbols (numbers). For this and more great ways to use beads and pipe cleaners in your math lesson, go to: http://commoncoreconnectionusa.blogspot.com/2014/12/beaded-number-rods.html
Build ice cream scoops counting by 10's This could be used to help students learn to skip count by 10's. Students will like this because it is bright and colorful. Teachers could use this as whole room instruction to teach them how to skip count