Monday, May 18, 2009

Sean's Multiplication Method

So much for trying to teach Sean The Method. He has his own Sean Method.

Last Thursday, I had to attend a Middle School transition talk and the boys waited for me in the school lounge (a big hall with comfy sofas just outside the cafeteria). Kelsey, Brian's classmate who had asked Sean a division problem some days ago, came by, this time with her older sister and older sister's friend, and asked Sean what 37 times 28 was. This incident was related to me at bedtime just now.

I asked Sean if he got the answer. He said he did. I said How?? Did you use the method mummy taught you? No, I did it my way. Here's what he did.

"First I found three times of 37.
Then I doubled it.
Then I added 37 to it.
Then I doubled it.
And doubled it again."

So here's what he did;
37 x 3 --> 111
Double that --> 222
Add 37 --> 259
Double that --> 518
Double again --> 1036

He's using his knowledge of prime factorisation (learnt from Murderous Math) to do multiplication.

I asked him, "Why is it that when I ask you to do double digit multiplication, you say you can't; and when Korkor's friends ask you even harder ones, you manage to do it?"

He thought and said, "I think maybe it's because I don't try when you ask me."

!!! In other words, he'll put in effort to impress the girls, but won't do it for mummy.

10 comments:

monlim said...

Sean, Sean, how did you get to be so smart?? Wah, I'm really impressed.

Yalah Mummy, of course impress the girls more important what! Girls are going to fall at his feet in awe next time, you just wait and see!

Lilian said...

LOL! I don't think girls ever fall at feet of math nerds, just the rugby and soccer stars.

Sean has become like a performing monkey! Poor kid, stress man. Some day, he's gonna go hide every time he sees his korkor's friends.

monlim said...

Au contraire, I imagine Sean must love the attention! Brainy guys are hot lah, soccer and rugby stars are king only in ang moh countries. Just wait till you come back to SG!

Lilian said...

Sure not Mon? Soccer & rugby stars are always highly sought after everywhere.

And if we're back in Sg, he won't be special anymore, so many brainier brainiacs there. So he better bask in the attention he's getting here.

Anonymous said...

Your little Sean is truly amazing!!! *envy*

Mon is right,....wait till you come back to SG, heeeee ^_^

Chris

Lilian said...

He's not like this all the time Chris, and he didn't find the answer in superquick time like abacus- and kumon-kids.

He definitely doesn't perform like this when I give him work. So if he's given work in Singapore, aiyohhh, shudder to imagine him whining to his teachers...But I caaaaaannnn't dooooo ittttt.....

Alcovelet said...

Haha! So funny to think of Sean trying to impress the girls!

He's got the goods up there for sure! So whether he does it for you or for the girls, he's doing it. next time, got to revise with girls. This, he'll relish!

Anonymous said...

My dear, your little Sean could understand the prime factorization all by himself by just reading up the MM leh, dun be greedy hor....

By the way, to do fast calculation, I believe it can be trained. To each its own, I'm not keen in making my kids a walking calculator. :-P

Chris

Lilian said...

Ad: So next time there's a damsel in distress, chivalrous RK will jump right into the sea to rescue her while Sean will spout mathematical formula by the beach...hehe.

Chris: Nope, not greedy at all. I also don't need him to be walking calculator, esp since calculators are allowed in PSLE :P

Alcovelet said...

Sounds like a good deal. Then they both get the chicks!