Friday, March 4, 2011

Operations with Decimals

Today we talked about repeated addition with whole numbers and multiplication. An example of this would be --- 4 x 0.3 you would have to take 0.3 and add it four times, like so ---- 0.3 + 0.3 + 0.3 + 0.3 = 1.2.
We all so learned how to multiply decimals together and to move the decimal by how many places are behind thedecimal. This picture below shows the way to do it.

                                                                            picture by coolmath.com
We talked about division with decimals with the Powers of Tens. An example of this would be----the number---2.3798662 / 1000 the question is which way would you move the decimal? the answer is  to the left because we are dividing into 1000 pieces. I really like the refresher on decimals i had forgotten alot of it.
I just want to say i enjoyed the cookie very much.
                                                                 



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2 comments:

  1. Kells Bells' BlogMarch 7, 2011 at 10:05 PM

    I have a really hard time remembering in multiplication if 2 x 3 is 2+2+2, or 3+3. I try to remember the example we had been given; n x s= s+s+s... something like that. Had I not written it on my little test 3x5 cheat-sheet, I would have forgotten it. I do like thinking of it as repeated addition though, Teaching-wise, I think that's a good concept to pass along.

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  2. hgswansonMarch 8, 2011 at 7:12 PM

    I really like the picture to help visualize how to do operations with decimals. It especially helps me because I learn a lot easier with visual aids.

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