Division of 28 by 13Date: 9/12/96 at 12:22:12 From: Alicia Z Menchaca Subject: Division of 28 by 13 Can you divide seven into twenty-eight thirteen times? Date: 9/12/96 at 17:42:56 From: Doctor Jodi Subject: Re: Division of 28 by 13 Hi Alicia! One of my favorite ways to look at division is by grouping numbers. For example, if I wanted to put 8 items into rows and columns, I could do this several ways. I could make 2 rows and 4 columns: ** ** ** ** (2 X 4) or 4 rows and 2 columns: **** **** (4 X 2) Division is like grouping: You could also say that 8 divided by 4 (rows) is 2 (columns). Does that make sense? Is there any way to put 8 stars into 3 rows? Sort of... I can draw a picture like this: *** *** ** I'm missing 1 star here. Or I could do this instead *** *** and leave ** lonely stars somewhere else. We have problems grouping 8 into 3 rows because 8 doesn't divide by 3(rows) evenly. We're left with either too few or two many stars. You can do the same thing with the numbers you sent us. If we put twenty-eight stars into 7 rows here's what we get: * * * * * * * * * * * * * * * * * * * * * * * * * * * * Do you see that there are 28 stars in those 7 rows and 4 columns? What if we try using 13 rows? Well, then the grouping doesn't work quite as well: * * * * * * * * * * * * * * * * * * * * * * * * * * There are twenty-six. We still have 2 stars: ** and no good place to put them. 7 divides 28 evenly: you get 4. But 13 doesn't divide 28 evenly: you get 2 columns with 2 stars left over. I hope this helps. Let us know if you have any questions! -Doctor Jodi, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
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