Thursday, January 17, 2008

Multiplication tables.

A friend of mine stresses about unschooling - he stresses about homeschooling in general, but unschooling puts him over the edge.

We had a discussion one day about how unschooled kids would learn their multiplication tables and how vitally important it is to actually memorize them. I started laughing because I have *never* memorized my multiplication tables. Sure, I can *do* all of the multiplication and, if asked to recite them in the table form, I could do it, but I can't just ramble them off as a memorized "fact".

"Isn't what I can do more effective?", I asked him. No. According to him, it's the memorization that needs to happen. Never mind that I can figure out the answer to a multiplication problem in my mind quickly and correctly using math "tricks" and shortcuts. I should be able to ramble the facts off in order and at great speed.

I saw this posted on one of my unschooling lists recently. The question had come up - again - about multiplication tables and at what age your child should learn them. My favorite answer to almost any unschooling question was given (your child can learn anything they need to quickly and efficiently when they have the motivation) along with an example of how many facts they actually have to learn when learning the multiplication table.

"If your 15-year-old still didn't have the times tables memorized, but
then got a part-time job that somehow required those math skills, do
you not trust that she would at that point take it upon herself to
learn them, and would subsquentially become more and more versed in
them as she used them in the everyday life of her job?

I see people fret more about times tables that almost anything else
when it comes to math. Really though, if you're motivated and have a
need to do so, it would not take that long for most people to
memorize them--certainly not years, or even months or weeks! Look:
there 100 facts in the 10x10 table, but only 55 unique ones thanks to
twin facts/commutative property, minus 19 for the 1's and 10's which
are cake, minus 8 more if you know your doubles, minus 7 more if you
can count by 5s...that only leaves 21 facts to memorize. Learn the 9
trick and you're down to only 15. Only 15 facts to learn at age 15,
so that you can do your job well and earn money to save up for
a car or a Wii or whatever...what teen wouldn't be able to pull that
off?"

4 comments:

Stephanie S. said...

bah - I can figure it out in my head faster than I can figure memorization minus/plus/excluding whatever the equation calls for.
I'm impressed with your quick deductions, by the way.
My girlfriend always asks me "what's 6 x 7?" when we're on the phone, and she needs to know.
At work - where she manages money and finances - she has a calculator. (which she uses proficiently. :) )
And there you have it!

Tuan's Princess said...

Well said Sarah!

green said...

I see value in the ability to calculate in your head as opposed to dependence on calculators. That said, math tricks are much more effective than rote memorization (...I'm glad that came up in the post!)

6x7... well I remember 6x6 is 36... add 1 more 6 that is 42. And that folks is how I do it in my head. 142 x 20? 142x2 is 284... add a 0 for 2840. I practice doing these tricks all the time (like figuring tip for a meal etc.)

Vicki said...

I've watched my 4 year old already show signs of learning about multiplications but on his own time and his own way. One day we looked at these cards for a memory came. They were stacked in 3 rows with 4 columns. He quickly said look mommy, 3 groups of 4 make 12. No memorization here! I loved it.

I have to say I really don't have any worries about unschooling except for some neighbor or family member not getting it and making trouble for our family.

You are so right, they will get it when they are ready.