Teach-Primary-Issue-19.1

Creating potions has long held a fascination with children, whether that’s combining leaves and petals from the garden, or immersing themselves in the gloopy wonderfulness of slime. This investigation will help pupils to realise that ‘mixing potions’ isn’t just a fun activity – it’s what’s scientists do all the time, with the results of creative chemistry sitting in their bathroom cabinet! Through their own experiments they will unlock their understanding of the properties of materials and how they can be combined to create a highly effective toothpaste. 1 | CREATE The equipment you will need for the investigation can be easily sourced in local supermarkets, chemists or online. You will need: • Toothpaste-making ingredients: Baking soda (sodium bicarbonate), cornflour, salt, glycerine, peppermint flavouring, food colouring, water, teaspoons, yoghurt pots or plastic beakers. • Optional ingredients: Additional flavours and colourings to allow for formulation variation. • Testing equipment: Clean toothbrushes, white tiles or old plates/saucers, permanent markers. Having already set the context in the starter activity, discuss common toothpaste ingredients and the role they play in the formulation. What does baking soda do? (Gentle abrasion/reducing acidity). Why is peppermint used for flavour? (It’s considered to be a fresh, clean smell). Why is glycerine important? (Helps to hold moisture and prevent the toothpaste drying out in the tube). This background information helps the children to understand the purpose of each ingredient and sets the stage for their experimentation. Divide pupils into small research teams and provide them with the materials to make their own toothpaste; each team will create their own formulation, which will be START HERE MAIN LESSON WHAT THEY’LL LEARN l How the various ingredients within toothpaste have their own properties, which all have different functions l How to design, create and test different formulations, utilising numeracy skills l How to record observations, make comparative judgements and draw conclusions Science The end goal of this lesson is for the children to create and test their own toothpaste formulas. It could be fun to set the lesson within the context of a national toothpaste crisis: some toothpastes aren’t cleaning properly, others taste strange, and some even fall off the toothbrush too quickly! Toothpaste companies are baffled and need expert help. Explain to pupils that they will need to explore various ingredients, experiment with their combinations, and evaluate how well their toothpaste cleans, smells, and stays on the brush. This is also a great opportunity to emphasise the creativity and imagination intrinsic within science. Clever chemistry and the science of smiles Transform an everyday chore into an opportunity for exciting STEM adventures with Marc Bowen KS2 LESSON PLAN @raglanvcprimary 72 | www.teachwire.net