Last week, I was helping the 3rd graders with comparing fractions. Their teacher allowed me to use cross multiplication!  I told her, "Thank you!".  She told me she understood why they don't teach cross multiplication but, she said that it was the simplest way to compare fractions and the kids needed to know some "tricks" in order to get the math done. (Or something like that)

 

Anyway. What is your opinion on using cross multplication? The argument against it involves not being able to explain WHY it works?  I am unsure, really. Does it mess up math further down the line?  Why does it work?  Also. Why are 4th graders solving for x anyway? Isn't that algebra? I thought we saved algebra for 9th grade?  (Ha ha. Not really. I know my kids had it in 7th or 8th?)

I ran 60 laps, 12000meters, on the indoor track at the school i teach at,  It was raining pretty hard outside and I am lucky to have this facility at my use.

I am a mathematician and my concern about the use of cross multiplication in the third grade is that the students may not/probably not understand what they are doing.  Too many of my current college students fear math because they were taught these magical tricks that they could use to do one computation or another that they don't understand and appear to them to be magic.  They work for one use but not for another.  It would be great if the teachers could explain why the trick works and repeat again why it works and repeat again why it works and on and on so that the students will eventually understand it is just logic and not magic.  the problem I have is that many students just try to use tricks that they sort of learned but don't really understand what they are supposed to do  to perform the trick and what the steps are.

It is great for those who do understand the tricks but too many don't.  One of my goals in teaching the math phobes is to try to do some unusual math topics that  are far from the math they have seen before and they may be able to understand and to give them some success in the subject.  It is tough.

 5.3 miles on the TM tonight. I don't know, Mariposai, I always try to convince myself it's not a a cop-out move when things are a little dicey outside. I'm just really wary of slipping and falling on ice. Did that a couple years ago and it was not fun.

Erika - just as nobody ever accused Christine Clark of a cop-out when when she was running on a treadmill day-in-and-day-out in her Anchorage home with the heat turned up to simulate the conditions she'd be encountering for the women's trials in South Carolina in 2000, the word cop-out is never going to be applied to someone for whom we are in constant awe every day when we think of the elevation of the Equinox Marathon you run every year as if it is normal, . . or every week up Ester Dome and the like, . . . to say nothing of the moose, snow machines and mushers in your way, . . . or dark all the time in the winter, . . . or ice skate conditions,  . . . . . . ..  Just to be sure, do you still have the Ice Goddess photo in case anyone has forgotten how awesome you are?   I bet Christine doesn't have one like that.

Incidentally, it must have worked because Christine not only came out of nowhere to win the trials but became the sole runner good enough to represent the U.S. in the women's marathon in Sydney that year.  Viva Alaska goddesses!

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I think someone needs to be a co-storyteller with posie if we can do a story hour

at the Portland Marathon reunion, maybe Friday night or sometime?

MikeE, you are a good writer. I enjoyed the poem for your friend the other day.