Materials: 

borax

washable white glue

water

food coloring (optional)

plastic baggie

styrofoam beads (for Floam) -- buy at craft stores or take apart an old bean bag!

Procedure:  Combine 1/2 c. water and 1/2 tablespoon borax; stir until dissolved.  Separately, mix 1/4 c. water and 1/4 c. glue; add food coloring as desired.  Combine both mixtures in the plastic baggie until slime is formed!  Refrigerate when not using to prolong usefulness.

To make floam, add styrofoam beads to the mixture just before it firms into slime.