Common sense comes from experience, and kids need to fail as well as succeed in order to learn it. It's difficult to develop common sense when you spend a lot of time in your room where nothing much happens.

Be able to identify the most common breeds of dogs and cats on sight.

I would not encourage children or teens to multitask because we don't know where those efforts may lead.

Geometry is beautifully logical, and it teaches you how to think and prove that things are so, step by step by step. Proofs are excellent lessons in reasoning. Without logic and reasoning, you are dependent on jumping to conclusions or - worse - having empty opinions.

Know the function of a fuse box and the appearance of a tripped circuit breaker.

To acquire knowledge, one must study; but to acquire wisdom, one must observe.

Spending waiting moments doing crossword puzzles or reading a book you brought yourself.