Fractions scare me. I can't explain why, they just do. They rank right up there with graphs on my mathematical fear chart. I can now say those fears have been put to rest. I have learned to view the correct way to add, subtract, multiply, and divide fractions. The biggest lesson came to me when we began to review multiplication of fractions. Mixed number operations to be exact. I was wrong at first glance. If I were given a multiplication problem with mixed numbers, 2 1/7 x 3 2/5, I would have looked at it from two different angles. The first method would be incorrect, and lead me to an incorrect answer. I would have taken the 2 and multiplied it by the 3 to give me 6. Then I would have multiplied the 1/7 x 2/5. WHAT WAS I THINKING? The second way I would have gone about this problem would have been to change it to an improper fraction. This would have given me the correct answer, but it is not the correct way to view this problem. It all made sense once Mrs. Truelove said these magic words (and I parapharse) "If you had 27 x 32 you would not multiply the 7 by the 2 and the 2 x 3 to get your answer." BINGO!! It clicked. I need to distribute my numbers. Once I complete this process and find my answer, I can then go back and change my numbers into an improper fraction to check my answer.
Example of the problem mentioned in the post:
2 1/7 x 3 2/5
2(3 + 2/5) + 1/7(3 + 2/5) (distribute)
6 + 4/5 + 3/7 + 2/35 (now it looks familiar/ we need to find the LCD which is 35)
6 + 28/35 + 15/35 + 2/35 (add)
6 45/35 = 7 10/35 (reduce) = 7 2/7
Change to improper fraction:
2 1/7 x 3 2/5
15/7 x 17/5 (from here you can cross cancel)
51/7 = 7 2/7
I have checked my answer and found it to be correct.
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First let me say your blog page is the BOMB!!!! I agree on your blog about how you say improper fractions has given you a better understanding of fractions. I think it is so important to have the right understanding about MATH period.
ReplyDeleteOMG, I stink at graphs too! (lol)
ReplyDeleteIt's amazing how when learning how to teach our future students, we are learning completely new methods to use for ourselves. Sometimes all it takes is someone breaking it down in a very elementary way to make it all click. By the way, I love your blog page!