I ask this question of my 5 year old each morning over breakfast. A typical answer, which can be anywhere from 30 seconds to 30 minutes long (seriously), might be something like: "Well, first I'm going to be a Builder Peopleguy* and build a road, then I'll open up a store that sells electrical wires. After that, I'll be a Zookeeper Peopleguy and I'll specialize in snakes and lizards, and of course, I'll have to feed them...."
The 2 year old has begun to join in these conversations, too, and will usually indicate a desire to splash water in the sink or work on puzzles.
Then I talk about my own plans for the day: laundry, clean up the kitchen, the cabin business, pay bills, the garage project, any errands that need doing, etc.
I have found that having this little talk every morning and throughout the day as our plans change (as they inevitably do) helps us stay focused on our goals. I also get more cooperation when they understand that I have to do some things that aren't directly related to them. (They may not like it, but at least the older one understands. A little.) They help me stay on task, too: "Hey, Mom, weren't we going to put gas in the car today? How about that walk around the pond?"
But I think the most important benefit to them is that they see my husband and me setting goals, taking actions necessary to achieve them, using our minds to overcome obstacles, and our pride in living a productive life. Even if I don't finish each project as or when planned--sometimes they are multi-stage or we have to re-prioritize--I explain what happened and why. I share my frustrations and triumphs ("Yes! We finished assembling the bench for the garage!") and try to involve them in my own pursuits as much reasonably possible. For example, this afternoon Ryan helped me with our small furniture assembly project. I mean actually helped. He used real tools and screwed in bolts and hammered connector-thingies down and held the pieces in place when two sets of hands were necessary.
By modeling the virtue of Productiveness (as well as the other virtues), we are setting valuable examples for our kids to follow. We're showing them the way we think is right, telling them to do as we do.
And as is the case with all small children, they do want to follow our example. In the safe haven of their home, they decide on goals of their own interest, plan how to achieve them, and perform the actions necessary to achieve them, and we grownups make sure to give them space and time. The work of a child is to learn about reality, including how his own body and mind work. When kids follow the examples we set, they practice being adults, they learn and practice the habits that will help them achieve their goals as adults. Our job as their parents is to let them get on with that work. And so along the way, we answer their questions, make problem-solving suggestions, provide materials and other resources (and by that I of course mean stickers and electrical wires), and are ready with encouraging words and sympathy if necessary. But above all, we stand back and try not to interfere too much. Their work is and should be theirs.
When my kids declare that they want to read a book or build a tower or go for a walk or make cookies, they are setting goals in order to gain or keep their own values. Sometimes, no declaration is made out loud or needed (especially in preverbal kids, obviously). Kids simply do. They will jump off a step stool a hundred times. They might spend hours splashing in the sink. So they choose, sometimes they plan, always they act, and in this way even small children exercise the virtue of Productiveness.
When focused on an extremely difficult task, such as putting a puzzle together, or contending with unwieldy pillows that need to be shaped into a tunnel, or facing a sibling whose idea of "help" is somewhat different from one's own, children are exercising their own minds, their burgeoning Rationality.
When my oldest exclaims that he just loves to work hard on his own projects, when he jumps up and down after successfully hammering in a plastic dowel, when he excitedly calls me over to look at the road he designed and built, he is experiencing the result of Productiveness for himself--Pride.
Watching my kids beaming with pride is one of the supreme joys of being a parent.
"Productive work is the central purpose of a rational man's life, the central value that integrates and determines the hierarchy of all his other values. Reason is the source, the precondition of his productive work--pride is the result."*Peopleguy is the word my son invented at the age of about 20 months. It means "worker" but we've used it for so long it just rolls of the tongue (and out of my fingers on the keyboard) automatically.
--Ayn Rand, "The Objectivist Ethics," The Virtue of Selfishness, p 25