Dividing Decimals

[bmg10]

This is an odd situation. My daughter is in 5th grade, and her teacher so far this year has marked at least one, sometimes numerous, questions wrong on each of her homework/tests that were actually correct. I have sent notes that brought this to her attention, but it was only corrected without a word. I helped her with her homework last night and was told that again, it is wrong. My husband and I both got the same answer and tried to look at it different ways. It seems to be the simplest problem, but I may be crazy! Please help so I can move forward and decide what to do next!

Question:

The total weight of 6 pieces of butter and a bag of sugar is 3.8 lbs. If the weight of the bag of sugar is 1.4 lbs., what is the weight of each piece of butter?

Thank you

 

[Deleted member 4993]

This is an odd situation. My daughter is in 5th grade, and her teacher so far this year has marked at least one, sometimes numerous, questions wrong on each of her homework/tests that were actually correct. I have sent notes that brought this to her attention, but it was only corrected without a word. I helped her with her homework last night and was told that again, it is wrong. My husband and I both got the same answer and tried to look at it different ways. It seems to be the simplest problem, but I may be crazy! Please help so I can move forward and decide what to do next!

Question:

The total weight of 6 (identical) pieces of butter and a bag of sugar is 3.8 lbs. If the weight of the bag of sugar is 1.4 lbs., what is the weight of each piece of butter?

Thank you

You can solve the problem, if you assume that the pieces of butter were identical to each other.

The total weight of 6 pieces of butter and a bag of sugar is 3.8 lbs.

the weight of the bag of sugar is 1.4 lbs.

the weight of the 6 pieces of butter is (3.8 - 1.4 = ) 2.4 lbs.

the weight of the 1 piece of butter is (2.4/6 = ) 0.4 lbs. or (0.4 * 16 =) 6.4 oz

 

[bmg10]

Thank you

Thank you! That is the exact answer that we both got. This came from the New York State Math module, and it has been a very frustrating time for all of us. Have a great night!

 

[HallsofIvy]

I can't help but wonder what the problem really was! Saying "bag of sugar is 3.8 lbs." and "the weight of the bag of sugar is 1.4 lbs." is, at best, ambiguous! The responders are treating "the weight of the bag of sugar" as the weight of the bag itself, empty of sugar, but that certainly is not obvious to me.

 

[Deleted member 4993]

I can't help but wonder what the problem really was! Saying "bag of sugar is 3.8 lbs." and "the weight of the bag of sugar is 1.4 lbs." is, at best, ambiguous! The responders are treating "the weight of the bag of sugar" as the weight of the bag itself, empty of sugar, but that certainly is not obvious to me.

HoI - you need to drink another cup of coffee and read the problem statement again!

The problem is not that ambiguous!!

 

[HallsofIvy]

HoI - you need to drink another cup of coffee and read the problem statement again!

The problem is not that ambiguous!!

Since "1.4 pounds" is considerably less than "3.8 pounds" I won't say that assuming that "bag of sugar is 3.8 lbs" refers to the bag and sugar contained in the bag while "the weight of the bag of sugar is 1.4 lbs." refers to the weight of the bag itself is not a reasonable assumption but it is still an "assumption" that certainly would not be warranted by the words "bag of sugar" and weight of the bag of sugar".

Besides, 1.4 pounds seems awfully heavy for a paper bag that will hold only 2.4 pounds of sugar!