I think the world would be a better place if everyone graduated high school with this knowledge:
Meal planning and preparation. How to plan a set of meals for the week, make a grocery list, buy what’s on it, cook and freeze meals, and clean up.
Sure, some people like to eat European-style by buying fresh ingredients at the market every other day, but meal-planning skills ensure you can feed yourself real food no matter what else is going on in your life.
Suggestion: Take young kids on a field trip to the grocery store and show them how to choose a ripe pineapple or pick the best cut of discounted meat. Get older kids to browse through recipes and pick a meal to make at home, and report back on how it went (with photos).
Exercise. How to run, stretch, and lift weights properly.
Emotional resilience. How to recognize and accept your emotions.
Suggestions: Set aside time every week for kids to meditate and write a journal entry.
Safe sex. (As in, what it is.)
How to make small talk.
Lots of people claim not to like small talk, but as Linda Grant says, there’s no such thing as depth without surfaces.
Knowing how to speak to a stranger makes it easier to find the people you really connect with. (You need the surface-level small talk conversation to come first, before you can get to the deep stuff.)
And if you don’t know how to make polite conversation, people will think you’re weird. Maybe you don’t care what they think, but why make your own life harder and more unpleasant than it needs to be?
Suggestion: Teach kids the three fundamental icebreaker questions: Where are you from, what do you do, and what do you do for fun? Get them to practice asking these questions to strangers and listening to the other person’s response (active listening), as well as coming up with succinct responses.
(Instead of “Where are you from?” which rubs some people the wrong way because it implies they’re not from wherever you’re currently located, you could ask “Where do you call home?”.)
Teachers try to make you learn public speaking by forcing you to do presentations, but that just teaches you to prepare a report and read it out loud. Plus, since it happens so rarely, you don’t get enough chances to receive feedback and implement it.
Suggestion: Give students lots of opportunities to speak briefly and informally in front of the class. Weekly or even daily rounds of Toastmasters-style table topics (2-minute unprepared speeches) would be a great way to improve quickly.
How to participate in a group discussion.
The scientific method.
The metric system.
Critical thinking. How to argue based on logic (as opposed to just repeating what an authority figure said), and how to identify logical fallacies. How to evaluate the evidence for what is true, as opposed to believing in what one wishes were true or “feels” is true.
This one might be a lost cause because so few teachers are able to think critically (just look at how many of them are religious).
Suggestion: The book I used to study for the LSAT, Mike Kim’s LSAT Trainer, contains some incredibly useful drills for learning how to find the flaw in an argument. Have students do these drills, then apply what they’ve learned by listening to politicians’ arguments and identifying the flaws in them.
Suggestion: Let students write essays about interesting things, not just “symbolism in Dickens,” to quote Paul Graham (I pretty much agree with everything he has to say on this subject).
Other languages. These should be taught through conversations—by getting kids to speak to each other in class in the language they’re supposed to be learning—so that they learn how to actually say something useful, as opposed to merely knowing the words for a bunch of colors and zoo animals.
Self-organization. How to work on a fixed schedule.
I strongly disagree with the idea of homework. Kids should be given an amount of work that they could reasonably get done in a 7.5-hour school day (including classes and lunch), so that once they leave the school they’re free to relax, have fun, and got a healthy amount of sleep.
(I went to a high school that threw tons of lessons and homework at us and thought that would automatically teach us to be organized. Instead, I did everything at the last minute so that I would be forced to get things done faster, and went without sleep whenever that something took longer than expected.)
Suggestion: Provide just enough schoolwork so that kids need never take work home with them so long as they work hard during the day.
Investing. How to manage your money.
Suggestion: Teach kids that the key to becoming wealthy is not to win the lottery, but to spend less than you earn, say no to things you can’t afford, open registered investment accounts as soon as possible, and put your money in broad-market index funds.
Economics. How the economy works (and why the supply-demand curve is not the sole determinant of what is sold and at what price).
How to read quickly.
The principles of art.
I’m not saying beauty is a moral imperative, but sometimes things are ugly when they could just as easily have been beautiful. This is a waste. Teaching kids the principles of art will prevent at least some needless eyesores from being created.
Suggestion: Read books about art out loud to the class and show them the pictures. I highly recommend the book Art in Everyday Life, which was published in 1929 and still holds up today (because the art principles are timeless!). You can read it for free online here.
How businesses work.
Suggestion: Teach kids that businesses generally make money because they make stuff people want to buy (or because they somehow make people want to buy their things) and they sell it for a higher price than they paid for it.
I like Patrick McKenzie’s distinction between jobs and businesses: “A job is a system that turns time into money, and a business is a system that turns systems into money.”
(Another way businesses make money is by exploiting an inefficiency—such as by producing something solely because the government is handing out money for it, even though no one wants or needs it—but this isn’t something we want to encourage kids to do.)