Wednesday, February 11, 2009

Ferocious Fractions

Death by fractions - that's what will be written at the top of my headstone. Big Sister has been learning about equivalent fractions, and simplifying fractions. Today she was comparing fractions with different denominators - ie. she had to come up with a common denominator to determine which fraction was greater. This was easy enough when comparing denominators like 3 and 6, or 2 and 10, but then we came upon 7 and 5. It became obvious that she didn't quite get it yet.

Fortunately we've gotten to a point where she'll let me know early on that something isn't making sense. Usually I get a "vibe" from her that tells me she's basically smiling and nodding. Then I ask "Does this make sense?", and she'll kind of start off with a nod that becomes a head shake. So I explained, again, with different words and visuals. We backed up and looked at equivalent fractions one more time, and how 21/35 was really 3/5, and that it was hard to just eyeball 4/7 and know whether it was bigger or smaller, but when we changed it to 20/35 then we can know for sure. I think she gets it now. We'll see if she retains it overnight...

6 comments:

Six Green Zebras said...

I think you lost me. Math was by far my worst subject and fractions - ick.

The Beachbums said...

I'm with you Six Green Zebras. If our nieto is getting this she is definitely smarter than her abuelita.

Laura K. said...

You'd be surprised how quickly it all comes back. On the first day we started fractions she was supposed to identify the numerators and denominators... I was completely drawing a blank. For your future reference, "denominator" is on the bottom - it starts with the letter d, just like "down".

Anonymous said...

We've been working on fractions, too.

I tell the boys to picture it as a pizza (such as when trying decide if 2/3 is more or less than 3/4), or as money. That's been helping.

Laura K. said...

Kila, we do something similar. I'll ask "Would you rather have 2/5 or 2/7 of a chocolate pie?" "Would you rather have 1/4 of the creamed spinach, or 1/10?" Makes it more fun. When comparing more "obscure" fractions (like 3/5 and 5/7) it's too hard to visualize what that would look like, so she really should be working to come up with common denominators. Now Lattice Multiplication? glad I'm not dealing with that! ;P

JenPB said...

That's EXACTLY how fractions work in our house - we associate it with FOOD and they figure it out in a HEARTbeat! :)

Thanks for the nice comment on my blog, too. I'm glad you're enjoying it and finding ideas for your family, too. The PJ thing would be a great Girl Scout project!