A Socrative was used in connection to a textbook page to help students with practicing adding and subtracting fractions with unlike denominators. Ten problems were assigned and assessed. Scores will appear in GBW.
P.O.N. - Problem of the Night
Mr. Giomini is famous for his pies. He has been making pies in his bakery for several years. He knows that it takes 1 2/3 cups of flour to make his special pie crust. He buys flour in 25-pound bags and knows that each pound contains about 3 cups of flour. How many pies can he expect to make from a 25-pound bag of flour?
Answer to 11.11.14 Question: The question can be answered using division because we are asked to determine how many 2/3 sections go into 8/3 of length. We providing a reasonable estimate and then an exact answer. Since both denominators are thirds, I would look at the numerators and see that 2 goes into 8 exactly four time; my estimate would be four.
When performing the calculation of 8/3 divided by 2/3, I would take the reciprocal or 2/3 which is 3/2 and multiply that fraction by 8/3 giving me 8/3 * 3/2. I would use cross reducing, I would cancel out the threes because their common factor is 1 and the two and eight share a common factor of two making the two a one and the eight a four. The new fractions are 4/1 * 1/1 which equals 4 times that 2/3 goes into 8/3.
- apply and extend previous knowledge with multiplication and division to work with fractions.
- apply and extend previous knowledge understandings of numbers to the system of rational numbers.
For Evening Practice, the student is expected to...
- complete Khan Skill: Fractions as Division by a Multiple of 10.
I think it would be 45 pies I know this because 1 2/3 is the same as 1.66 and 1.66 will be the dividend and 25x3 is 75 and 1.66 divided by is 45.1807228916 so 45 pies
ReplyDeleteMastnardo
Mast,
DeleteYou went a different route converting the 1 2/3 into decimal and then dividing. I like that approach and it does help with our dividing by decimals skill that was practiced early in the quarter. Why did you choose that algorithm rather that using the reciprocal of 1 and 2/3 and times it by 75?
I got 14/3 because I did 1 2/3+3/1 then I converted 1 2/3 to an improper fraction then added 3/1 and got 14/3
ReplyDelete1 2/3+3/1=14/3
5/3+9/3=14/3
Stiles,
DeleteTake a look at some of the other explanations. You need to begin by figuring out how many cups of flour are in the 25 lb bag because that bag is going to be broken into/divided by 1 2/3. We then have division of fractions meaning we need to work the reciprocal of the second fraction.
The answer for the problem is 45.I got my answer by knowing that it said that Mr. Giomini bought 25 pounds and he knows that 3 of those pounds is how much 1 pound equals. So to figure out the total I simply multiplied and got 75. Once I got 75 I divided it by 5/3( I turned 1 2/3 into a mixed number because when dividing you cant have a mixed number) because then they wanted to see how many he made so then that told me that you should divide 75( how much he had) by 5/3 ( how much he wanted to see could go into 75.)
ReplyDeleteKnickerbocker
Knickerbocker,
DeleteI agree with your answer. In your second sentence, remember that 1 lb of flour equals 3 cups of flour and that you have 25 lb meaning that 25 lb x 3 cups per pound give you the 75 cups in a 25 lb bag. Nice explanation of turning the mixed number into an improper fraction.
I got my answer by 25 * 3 =75 and then I took 75/1 and divided it by 5/3, and I used the reciprocal for 5/3 which would then turn into 3/5 and then when I multiplied to get my answer of 45 pies.
ReplyDeleteKeith :}
Keith,
DeleteAnother nice post from you. Nice use of the word reciprocal and you applied it appropriately in your explanation. Thanks for contributing.
I think that he will be able to bake 75 pies. I think this because he said he bought 25 pounds of flour and one pound of flour makes three cups. So then 25 x 3=75. He said it takes 1 2/3 cups of flour to make one pie. So 75/1 \ 1 2/3. But you have to change a mixed number to an improper fraction. 1 2/3 as in improper fraction is 5/3. so 75/1 \ 5/3=45. So he can bake 45 pies.
ReplyDeleteSummers,
DeleteI like the final answer and use of division to help you solve the problem. Do you think 75 pies or 45 pies because you stated two different answers?
My answer is 45 pies, because 25 *3=75 cups*3=225 cups and 225/5=45 pies.
ReplyDeleteVotruba 3rd period
Truba,
DeleteNice job of getting on the explanation in as few as words possible. It is ok to elaborate on the thought process at times and explain why you did something in greater depth.
the answer is 45 pies. First I multiplied 25/1 and 3. Then I got an answer of 75/1 and last I divided 75/1 and 5/3 but to make it easier I did the reciprocal of 5/3 and changed it into 3/5 and multiplied 75/1 and 3/5 but to make it easier you can do cross reduction so 75 divided 5 is 15 and 5 divided by 5 is one so I am now multiplying 15/1 times 3/1 and that equals to 45. That's how I got the answer of 45 pies.
ReplyDelete-Smith 4*
Smith,
ReplyDeleteNice to you see you contribution to the blog. Good work with using appropriate verbiage in your explanation of your process for solving the problem.