Help your child learn where food comes from by planting a garden. Even a little patch of earth outside can turn into his 'farm'. If it's winter or you live in a town or city, make an indoor garden on a counter near the window.
Planting the seed
Plant radishes, beans and lettuce: They all grow quickly, so your child will be able to see the fruits of his labour in short order. Help your child to plant, water and harvest his crops. Be sure to celebrate when you're done! If you can, take your child to visit a real farm to watch the planting or the harvest.
An opportunity to learn
All of this teaches your child about consistent care and gives him responsibility, both of which are more important than the actual crops themselves. Don't expect too much from him at this age though – he'll need all the help he can get!