You can also separate the glue mixture evenly into smaller bowls and make each one a different color, then mix them together.
If you chose to make smaller amounts of slime in separate containers, evenly divide the borax solution among the containers. Start kneading the slime with your hands at this point. It might be sticky, but keep mixing. Add more activator (borax) if needed.
Wiggle the styrofoam around and the slime should follow it. Your kids will be amazed!