NG TOOTHPASTE Making

NG TOOTHPASTE Making Toothpaste/ Terrific Teeth pt 1 Activity Card The Bright Smile Toothpaste Company have sent you a letter: Dear Investigators, Here at Bright Smile Toothpaste Company, our scientists say that good toothpaste must: • Remove plaque and stains quickly • Have a pleasant smell for fresh breath • Stay on the toothbrush • Have an attractive colour We need you to help make and test our latest recipe. How will you test the four different properties? Our scientists are always interested in new ways of testing our toothpaste. Here’s our recipe: 3 teaspoons of baking soda (not baking powder) 1 teaspoon of cornflour 1⁄2 teaspoon of salt 3 teaspoons of glycerine 1-2 teaspoons of peppermint flavouring 1⁄2 teaspoon of food colouring (optional) 2-3 teaspoons of water 1. Mix together the baking soda, cornflour and salt in a container. 2. Add the glycerine and peppermint flavouring, and mix to form a thick paste. 3. Add a few drops of water at a time until the mixture is at the correct thickness. 4. You can add colouring as well. We look forward to hearing from you. Yours faithfully, MAKING TOOTH Ivor Cavity (General Manager, Bright Smile Toothpaste Company)

Your challenge Bright Smile Toothpaste Company wants you to help with some very important, top secret research. Read the letter to find out more. MAKING TOOTHPASTE Discuss Find out about toothpaste ingredients. Why do you think the toothpaste company has chosen these ingredients for its toothpaste? What are they for? Why do you think the food colouring is an optional ingredient? Do you think some colours would put you off using toothpaste? Why? Why do you think that mint is the most common toothpaste flavour? Plan what you are going to do, there are ideas on the back to help you. In the letter there are four things that it says toothpaste must do. How are you going to test the toothpaste for each of these without using real teeth? What will you observe and measure in each test? Are there other things that might make the toothpaste better? How will you test for these? Getting started To make the toothpaste you will need: Baking soda (sodium bicarbonate NOT baking powder), cornflour, salt, glycerine, peppermint flavouring, food colouring, water, teaspoons, yoghurt pots or plastic beakers extra flavours and colours (optional) To do the tests you will need: Clean toothbrushes, white tiles or old plates, permanent markers or shoe polish, additional plastic containers and/or plates and a covering for the table. You may want to use a grid like this to record your results, or you might think of a better way to keep notes. How does the toothpaste remove plaque and stains? Does the toothpaste smell fresh? How well does the toothpaste stay on the brush? Does the toothpaste have an attractive colour? Other tests you think are important…