Thursday, December 4, 2008

break through

B hit a bump in the arithmetic road. it was the letter n. "WHY would they use a LETTER in a math problem???" we were on the verge of a melt down. i had to think fast. and i came up with, what i think, was a great way to show the process of figuring these simple algebraic equations.

i set up the equation using the one cubes from a base ten block set, numbers and function signs on index cards, and a small jewelry box labeled n. i put the answer to n hidden in the box for B to discover.

to find the answer we need to take the 7 away from the left side of the equation. that means to keep it equal we have to also take 7 away from the other side.

7 minus 7 is 0 and 0 plus n is still n. 12 minus 7 leaves 5.

now open the n box to check your answer.
we had a break through!

does an 8 year old really need algebra? i wonder if other third graders are learning this?
everyday gift: a light bulb moment


Carol S said...

In my experience, most early elem math programs do have kids figure out things along the lines of 7 + ____ = 12. Many will use a blank line or box rather than using a letter variable.

I've never taught them how to solve it algebraically. I can't remember now what I did with my kid who is the most advanced in math. She just got it. I don't think I had to do anything.

I've used RightStart the most with everyone but her. The way you presented it would fit right in with using a math balance. (But cheaper than the math balance. ;) )

Thanks for taking the time to post it, and I'll certainly keep it in mind as I work through arithmetic with my last kid. :D Because you never, ever know if what you did with the previous kids is going to work with the next kid....

stacy said...

carol, this is my third time teaching horizons math and it was not a problem for the first two. (except that #1 could figure it instantly in his head and was very insulted that i wanted him to write the problem out. lol.)

and yes, about the scale, i was wishing i had one. i used my hands to simulate a scale.

Chris said...

It makes a lot of sense introducing children to algebra and basic rules early in their math education. Not every child at this age is ready for this concept... but since B "got it" I would expect many other math "hurdles" to fall. Good for you on being creative and imaginative. And does it matter what others are doing? I think one of the most significant benefits of homeschooling is doing things that challengs your child (rather than following the curriculum). Way to go B and Stacy!

stacy said...

you're right, chris. it doesn't especially matter what others are doing. i guess i reveal my insecurity when i ask that question! although it does help in a small way as i organize an appropriate curriculum.

thanks for your encouragement, friend! :o)