Much more practical subjects that can be applied to the whole of their adult lives, not just their careers.
Financial - children need an understanding of how money works - credit cards, interest rates, mortgages, loans, savings, vat, stocks and shares, pensions, different types of accounts etc.
Health - this includes everything from nutrition, exercise (no more sadistic pe lessons), the effects of 'vices', keeping yourself healthy, sexual health, lifestyles etc.
Parenting - Not as detailed as an antenatal course (although that might help reduce teen pregnancies) but general information for the future about pregnancy, birth, childcare etc., without age implications or moral judgement.
Transport - basic car maintenence, what to look for when buying a car (to avoid dangerous lemons), driving and cycle proficiency lessons (at extra cost), map reading, understanding signposts, train timetables, tube maps etc.
Household maintenence - how to use standard tools, replacing washers, bleeding radiators, putting up shelves, cleaning gutters, wallpapering, painting etc. Household safety - avoiding fire risks etc.
Most of the traditional subjects can stay, especially maths (but more emphasis on applied rather than pure), IT, Science, English, History, Languages etc., but more modular and flexible.