This is a learning and fun activity you can do with your kids and it's cost free! They will be excited to watch their plant grow as they take care of it, too!
I did this with my daughter this year. We chose a little, tiny pot (use any kind of vessel you can find, be creative) and after laying some cotton on the bottom of it we threw in some lentils and watered it. They need to be watered every day!
(Note: in the first pictures you will see a small pot with beans, as well. Don't try it! The stench a few days later was unbearable!!!)
Look how they were growing! And it didn't take long, at all!