Try making 3-4 different mixtures of paper using different paper starters. This will allow kids to find out what kinds of paper are best for recycling, and how changing the type of paper changes the final texture of the finished paper product.
Once the water is boiling, pour it into your blender with your paper pieces. The hot water will start to turn the carton into pulp. Place the lid on the blender and blend the paper pieces and water until it creates a soup-like mixture.