Many science experiments go at a certain speed, called their 'rate of reaction'. For example if you crack an egg into a frying pan, the rate at which it turns into a fried egg is dependent upon how hot the frying pan is; so temperature is the key factor that determines how long you're going to have to wait for your breakfast!
In this worksheet you are principally going to look at an experiment on sweets and you'll have to decide how important certain factors are in determining how fast the experiment goes.