distancia Posted September 9, 2010 Share Posted September 9, 2010 Maybe someone who is more "mathy" than me can come up with a way to explain a particular concept visually. I have no problem understanding the multiplication of fractions. Example: 1/6 x 2/3 = 2/18 = 1/9. If I were to draw this, I would make a pie with 6 segments, and then divide each of those segments (the sixths) into thirds (which would be a bunch of teen eighteenths), and take 2 of the 3 smaller segments from one of the (divided) sixths. Now, how can you do this visually with a pie, using division? If I have the same example as above, only division [1/6 divided by 2/3], I will end up with 1/6 x 3/2 = 3/12 = 1/4. How can I show a pie which has been divided into 6 sections, further divided by 2/3, and ending up with 1/4? Thanks for any verbal help or links to websites showing this pictorially. Quote Link to comment Share on other sites More sharing options...

regentrude Posted September 9, 2010 Share Posted September 9, 2010 1. If you need to visualize it I would begin by choosing a larger fraction divided by a smaller fraction so that you actually get a number of pieces. 1/2 divided by 1/4: you are trying to figure our how many 1/4 are in 1/2, that's what dividing is. So you take 1/2 pie. You divide it into 1/4 pies and count: how many 1/4 pies are in the 1/2 pie: the answer is two. Or take 2/3 of the pie and divide by 1/6 of a pie: you find that there are 4 1/6 pies in 2/3 of a pie. 2. Once that concept is understood, divide smaller fractions by bigger fractions: 1/4 divided by 1/2 is asking: how many half pies are in a quarter pie. the answer is of course : one half of half a pie. A better way of posing this question would be: how MUCH of half a pie is in a quarter pie. 1/6 divided by 2/3 is asking: how much of 2/3 of a pie is in 1/6 of a pie: There is half a third in one sixths, so there will be a quarter of two thirds in one sixth. This will be very hard to illustrate- so I would turn this around and use multiplication: 1/6 * 4 = 2/3 so (1/6) / (2/3) =1/4 At this point, I would find the pie more confusing than helpful. Quote Link to comment Share on other sites More sharing options...

justasque Posted September 9, 2010 Share Posted September 9, 2010 regentrude gave a great explanation. I wanted to add that I include a "story" that goes with it, usually having to do with a party and leftover pizza. So if you have 2 1/2 pizzas left over from the party, and you want to give the child 1/8 of a pizza (one slice) in his lunchbox, how many servings will you have? (2 1/2 / 1/8), which = (5/2 / 1/8), which = 20. Hopefully you'll be putting those slices in the freezer! Quote Link to comment Share on other sites More sharing options...

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