Secret Formulas: Making Toothpaste

Now that your student has tested all the ingredients available to make his own secret formulas of toothpaste, he can now choose how much of each ingredient to add, based on the testing he has done. Each ingredient (calcium carbonate, a mixture of 3 parts baking soda to 1 part salt, glycerin and soap {Ivory Snow}) has strengths and weaknesses and he has to choose how much of each ingredient to add based on which qualities (taste, texture, sudsing ability, cleaning ability) means the most to him. He also has flavors to choose from. Just gather food flavorings (such as coconut, cinnamon, peppermint, lemon, vanilla, chocolate to name a few). No sweeteners of any kind are to be added.

Fifth Student writes down what he has put in.

Fifth student product tests.

Related Posts:
Secret Formulas: Paste
Secret Formulas: Cola Taste Test
Secret Formulas: How Sweet IS Coke?
Secret Formulas: To Each His Own Cola
Secret Formulas: Ice Cream
Secret Formulas: Toothpaste
Secret Formulas: Testing Cleaning Ability

Source:
GEMS Guide Secret Formulas Grades 1–3 
Students eagerly investigate the properties of substances as they make their own personal brands of paste, toothpaste, cola, and ice cream. The activities have been designed to convey key science/mathematics skills and concepts, provide motivating real-life experiences with chemistry, and build comprehension of cause and effect, central to later understanding of controlled experimentation. Secret Formulas speaks to the need expressed by many primary school teachers for more high-quality physical science activities.