Recalling that a liter is 1000 ml or 1000 cubic centimeters, we will add 10 cc of corn syrup to a liter of water. Your ruler is marked in centimeters. So we want to add a slug of cornsyrup about 1 cm x 1 cm x 10 cm long. You can estimate this volume easily and you need not be exact for this first experiment. Read the label on your syrup.
Much syrup sold today contains corn syrup and high fructose syrup.
Fructose is sweeter than glucose and microbes can use both sugars. Tube your medium and sterilize your medium. Normally we put our medium in culture tubes, plug them with cotton, and then sterilize them. We will omit the sterilization step for this experiment. Later we will have an entire page on sterilization.