You need two plastic or disposable cups, a plastic spoon or craft stick and measuring spoons. Pour 4 ounces of warm water into one of the disposable cups and add 1 tsp. of borax laundry additive powder. Stir the mixture until it is completely dissolved. In the other cup add 1 tbsp. of glue, half of the borax solution and 1 tbsp. of cornstarch, and let the cup sit for 15 seconds. Stir the ingredients together until you cannot stir it any longer, and then kneed the mixture in your hands. Shape the mix into a ball as it becomes a solid.
Use white glue to make the ball opaque, and clear glue to make it transparent. Create a colored ball by adding three to four drops of food coloring to the glue before adding the rest of the ingredients. Add more food coloring to make the color darker. Try to make designs with different colors, and add glitter or confetti to make each ball unique.
Adapt and change the recipe to find the ball mixture that bounces the highest. Measure the height of the bounces of the different balls with a yardstick. Add borax to the warm water until it settles in the cup, and then continue with the experiment. Try different types of glue. Increase the amount of corn starch and glue, and test how high each ball bounces. Use different disposable cups and stirrers for each mixture and record the results. Change one variable at a time first, and then change multiple ingredients until the best result is found.
Substitute ingredients. Replace water with mineral oil or cooking oil. Kneed rubber bands into the ball. Substitute flour for corn starch and test to see if the ball holds together the same way or if you need more flour than corn starch. Powdered chalk, talc or baby powder can also replace corn starch. Add one ingredient at a time to the standard ball solution to discover what happens to the ball.