Thursday, April 07, 2011

The Mathematics of Huging my great Niece Jordan

I have already blogged about (trying to) teach me Nephew Jason math here and my Great Nephew Justin math here. Now its my Great Niece Jordan's turn.

I was at a dinner with relatives including my 12 year old great niece Jordan. There were 10 people at the dinner.

BILL: Jordan, if everyone at this table hugged everyone else, how many hugs would there be?

JORDAN: If I get it right will you give me a hug?

BILL: I'll give you a hug in any case.

JORDAN: Okay. 10 times 10... so 100.

BILL: Can you hug yourself.

JORDAN: Sure (she then hugs herself).

BILL: For this problem lets assume you cannot hug yourself. Then how many.

JORDAN: Oh, that changes things. Its 10 times 9... so 90.

BILL: If I hug you and then you hug me, does that count as one hug or two?

JORDAN: Oh, that changes things. How do you do it?

BILL: Your answer of 90 counted BILL-HUGS-JORDAN and also JORDAN-HUGS-BILL. The same is true for every pair. So every pair was counted twice.

JORDAN: So... is the answer (9 times 10)/2 ... 45 ?

BILL: YES! Great. (They hug.)

JORDAN: You're not just a great uncle, you're an AWESOME Uncle!

BILL: And you're an AWESOME Niece!


  1. Would you say that combinatorics, among other fields of mathematics, is the easiest way to get children in to learning math?

  2. YES I would say that since combinatorics does not need prior knowledge and the problems can be expressed in ways children can understand them.

    This scales up to High School Students
    and Ramsey Theory as well.

  3. AWW. That is such a sweet way of teaching math! I love it.

  4. If you teach her basic math skills, but not basic spelling skills, then she too might one day look rather perverse for "Huging" her niece instead of "Hugging" her.

  5. "huging" ? is that a spello garro ?

  6. I 10-choose-2 you, Pikachu...

    But seriously, I really like this. First you show kids that a specific computational problem is neat and then you can show how the techniques of mathematics enable one to scale up. Beats the hell out of just producing a formula and saying "this is how you apply it."

  7. Cool stuff. Now ask her if she can 4-color a 17 by 17 grid. The world is waiting.

  8. That is a great post, Sir. You really outdone yourself.