Washing powder investigation

A lesson including resources - I made for OCR entry level science - the cooking and cleaning module - although it can be adapted it looks at the effectiveness of washing powders- i intend a practical where they put prestained swatches of white cotton into beakers of warm water - stir it for a set amount of time and then rinse and dry the cloth - they mkae predictions about which brand of washing powder will be best and then see if they are correct - Data is a simple observation