Build/remove subtraction math center! An easy, hands-on approach to help students understand subtraction!
"One Fish, Two Fish, Red Fish, Blue Fish" - Addition Number Story
Pieces by Polly: Kindergarten Pi-Day Activities
Grades 1st through 3rd can enjoy this art lesson. Math is integrated with this lesson through shapes and reflections, students can use their imaginations and math skills to make a fun art picture which consists of shapes and colors.
Corkboard Connections: 5 Math Games Every Classroom Needs to Play
Teaching Addition with Popsicle Sticks - you could use any two different colored stuff around the house: straws, strips of colored paper, two different kinds of dried pasta/beans, etc.