amo_mea_filiis. Posted November 4, 2011 Share Posted November 4, 2011 (edited) Carlos wants to buy a bike for $366.38. If he makes weekly payments of $12, about how many weeks will it take to buy the bike? DD got a 76% on this math test! She got full credit (2pts) for this problem!!! Edited November 7, 2011 by amo_mea_filiis Quote Link to comment Share on other sites More sharing options...
Snickerdoodle Posted November 4, 2011 Share Posted November 4, 2011 nm a poll! Quote Link to comment Share on other sites More sharing options...
chepyl Posted November 4, 2011 Share Posted November 4, 2011 The answer is 30.5, you round up. Quote Link to comment Share on other sites More sharing options...
Parrothead Posted November 4, 2011 Share Posted November 4, 2011 30.53 So the last payment will not be a full payment but it will take 31 weeks to pay it off in its entirety. Now, if there were any late charges of fees associated with this account there will be a bit extra to pay off the last week of the loan. And the last payment could be more than $12 if there are fees involved. Quote Link to comment Share on other sites More sharing options...
QueenCat Posted November 4, 2011 Share Posted November 4, 2011 31 weeks. The last week is a lower amount. Quote Link to comment Share on other sites More sharing options...
Night Elf Posted November 4, 2011 Share Posted November 4, 2011 Well, it would take him 30 weeks to pay off 360 dollars. So I vote for 31 weeks. Exactly. There would still be $6.38 left to pay and he wouldn't be able to pay for that until the next week, the 31st week. It reminds me of problems that say 9 students are being driven to the zoo. 4 fit in one car. How many cars do they need? 3, because 4 each in 2 cars makes only 8 students. Unless they are going to strap the left-over student to the roof of the car, they need another car for him to ride in! :D Quote Link to comment Share on other sites More sharing options...
amo_mea_filiis. Posted November 4, 2011 Author Share Posted November 4, 2011 The answer on the test is 30. I want to ask dd's teacher if she can get credit for 31. Quote Link to comment Share on other sites More sharing options...
Snickerdoodle Posted November 4, 2011 Share Posted November 4, 2011 The answer on the test is 30. I want to ask dd's teacher if she can get credit for 31. I guess it would depend on whether the task was to estimate or to round. Here's to ambiguity! :cheers2: Quote Link to comment Share on other sites More sharing options...
Night Elf Posted November 4, 2011 Share Posted November 4, 2011 The answer on the test is 30. I want to ask dd's teacher if she can get credit for 31. I would, unless the teacher can prove to you that $12/week equals the amount of the bike. Maybe it's assumed the person has pocket money left over? :tongue_smilie: We use Keystone. I've sent in corrections for their courses and for the textbooks. Ugh. Quote Link to comment Share on other sites More sharing options...
luvnlattes Posted November 4, 2011 Share Posted November 4, 2011 The answer on the test is 30. I want to ask dd's teacher if she can get credit for 31. :confused: I would definitely ask.... Quote Link to comment Share on other sites More sharing options...
kiana Posted November 4, 2011 Share Posted November 4, 2011 There is no way for the answer to be 30, unless the problem specifically said to estimate. Perhaps the teacher was careless? I have seen math errors on marked work before. a) Since it deals with price, even if the price of the bike were 360.01 he would STILL not have enough money after 30 weeks. b) Even if applied, rounding procedures should round it to 31, although normal rounding procedures do not make sense here -- it must be rounded up. The example of children in cars is a good one as well. Quote Link to comment Share on other sites More sharing options...
Spy Car Posted November 4, 2011 Share Posted November 4, 2011 The answer on the test is 30. I want to ask dd's teacher if she can get credit for 31. The answer on the test is wrong. It is wrong on the "actual answer" and it is still wrong if one is rounding/estimating. Bill Quote Link to comment Share on other sites More sharing options...
amo_mea_filiis. Posted November 4, 2011 Author Share Posted November 4, 2011 18. (2 points) Carlotta wants to buy a mountain bike. The bike costs $366.38. She plans to make weekly payments of $12. About how many weeks will it take her to buy the bike? weeks ETA- This is copied and pasted from test. Call the teacher for credit of 31 weeks? Quote Link to comment Share on other sites More sharing options...
YourFidgetyFriend Posted November 4, 2011 Share Posted November 4, 2011 Things like this are why I've never been a math person. For example, if you make weekly payments and you make your first payment today, and your second payment next Friday, did you make those payments in two weeks? It's two separate calendar weeks, but not 2 weeks time. Drives me nuts, I tell ya, but it's probably just me. Anywho, yes I would call about credit for 31 weeks. Quote Link to comment Share on other sites More sharing options...
Night Elf Posted November 4, 2011 Share Posted November 4, 2011 18. (2 points) Carlotta wants to buy a mountain bike. The bike costs $366.38. She plans to make weekly payments of $12. About how many weeks will it take her to buy the bike? weeks ETA- This is copied and pasted from test. Call the teacher for credit of 31 weeks? I can see how the wording makes the answer 30, but I do believe a well presented case would give your child a chance at getting the points. Point out that the correct answer is 30.53 and therefore rounding would dictate going up to 31, therefore that answer should be seen as valid. Quote Link to comment Share on other sites More sharing options...
amo_mea_filiis. Posted November 4, 2011 Author Share Posted November 4, 2011 If she didn't have such a poor math grade, I might let it go, but to watch her do the work and do it correct only to get the answer wrong is annoying. Quote Link to comment Share on other sites More sharing options...
Spy Car Posted November 4, 2011 Share Posted November 4, 2011 I'm starting to see this might be one of those "how many pages did you read" type questions. If time is zeroed out at the moment of the first payment then 30 weeks transpire when the final payment (of 31) is made. The question (as asked) is very vague. Bill Quote Link to comment Share on other sites More sharing options...
Daisy Posted November 4, 2011 Share Posted November 4, 2011 30 weeks is totally wrong. I would talk to the teacher. LOL. Spy Car. You are going to make me start over-thinking it. Quote Link to comment Share on other sites More sharing options...
amo_mea_filiis. Posted November 4, 2011 Author Share Posted November 4, 2011 LOL. Spy Car. You are going to make me start over-thinking it. :iagree: LOL. She's 10 with only Everyday Math training. Quote Link to comment Share on other sites More sharing options...
Twigs Posted November 4, 2011 Share Posted November 4, 2011 Let’s look a simpler problem. $46 total, $12 weekly payments. 3.83 weeks, round up to 4 weeks. But look at it this way. 1st payment on Monday (total paid $12) then 7 days (1 week) later 2nd payment on Monday (total paid $24) then 7 days (1 week) later 3rd payment on Monday (total paid $36) then 7 days (1 week) later 4th (partial) payment on Monday (total paid $46) So, 3 weeks to pay off the debt. That is, 1 week less than the original solution of 4 weeks. So the solution to the OP problem 30 weeks (1 week less than 31 weeks). Quote Link to comment Share on other sites More sharing options...
mom31257 Posted November 4, 2011 Share Posted November 4, 2011 Well, 30 weeks is on $360, so is the teacher going to pay the other $6.38? I think the word "about" is implying to round off to a more general number. 30 is much more general than 31, but I think it is poor wording. Quote Link to comment Share on other sites More sharing options...
kiana Posted November 4, 2011 Share Posted November 4, 2011 I'm starting to see this might be one of those "how many pages did you read" type questions. If time is zeroed out at the moment of the first payment then 30 weeks transpire when the final payment (of 31) is made. The question (as asked) is very vague. Bill Yeah. Have they been taught to 0 time out when the first payment is made? Unless this has been specifically taught I would find marking 31 wrong as unacceptably vague. Quote Link to comment Share on other sites More sharing options...
Spy Car Posted November 4, 2011 Share Posted November 4, 2011 (edited) :iagree: LOL. She's 10 with only Everyday Math training. They are going to say: Payment 1=0 Weeks Payment 2=1 Week Payment 3=2 Weeks Payment 4=3 Weeks Payment 5=4 Weeks Payment 6=5 Weeks Payment 7=6 Weeks Payment 8=7 Weeks Payment 9=8 Weeks Payment 10=9 Weeks Payment 11=10 Weeks Payment 12=11 Weeks Payment 13=12 Weeks Payment 14=13 Weeks Payment 15=14 Weeks Payment 16=15 Weeks Payment 17=16 Weeks Payment 18=17 Weeks Payment 19=18 Weeks Payment 20=19 Weeks Payment 21=20 Weeks Payment 22=21 Weeks Payment 23=22 Weeks Payment 24=23 Weeks Payment 25=24 Weeks Payment 26=25 Weeks Payment 27=26 Weeks Payment 28=27 Weeks Payment 29=28 Weeks Payment 30=29 Weeks Payment 31=30 Weeks Bill Edited November 4, 2011 by Spy Car Quote Link to comment Share on other sites More sharing options...
Spy Car Posted November 4, 2011 Share Posted November 4, 2011 Yeah. Have they been taught to 0 time out when the first payment is made? Unless this has been specifically taught I would find marking 31 wrong as unacceptably vague. :iagree: Singapore Math is somewhat famous for including these sorts of questions, but the kids are prepared for them. Bill Quote Link to comment Share on other sites More sharing options...
YourFidgetyFriend Posted November 4, 2011 Share Posted November 4, 2011 30 weeks is totally wrong. I would talk to the teacher. LOL. Spy Car. You are going to make me start over-thinking it. This has always been my problem. In my English graduate program, none of us could do a word problem to save our lives. I've decided that people who have based most of their academic careers on nuances in language have also sacrificed the ability to do elementary word problems :lol: Quote Link to comment Share on other sites More sharing options...
joannqn Posted November 4, 2011 Share Posted November 4, 2011 Unless she was suppose to estimate, she should definitely get credit for getting the correct answer. Quote Link to comment Share on other sites More sharing options...
LizzyBee Posted November 4, 2011 Share Posted November 4, 2011 ...I think the word "about" is implying to round off to a more general number. 30 is much more general than 31, but I think it is poor wording. :iagree: I voted 31 weeks, but the word "about" implies we're looking for an estimate rather than the exact answer. So in my head, I think, well 12 goes into $360 evenly and $360 is close to $366, so about 30 weeks. But I think credit should also be given for a correct answer, i.e. 31 weeks! Quote Link to comment Share on other sites More sharing options...
Snickerdoodle Posted November 4, 2011 Share Posted November 4, 2011 In this case, with estimating, the answer is 29. :tongue_smilie: They are going to say: Payment 1=0 Weeks Payment 2=1 Week Payment 3=2 Weeks Payment 4=3 Weeks Payment 5=4 Weeks Payment 6=5 Weeks Payment 7=6 Weeks Payment 8=7 Weeks Payment 9=8 Weeks Payment 10=9 Weeks Payment 11=10 Weeks Payment 12=11 Weeks Payment 13=12 Weeks Payment 14=13 Weeks Payment 15=14 Weeks Payment 16=15 Weeks Payment 17=16 Weeks Payment 18=17 Weeks Payment 19=18 Weeks Payment 20=19 Weeks Payment 21=20 Weeks Payment 22=21 Weeks Payment 23=22 Weeks Payment 24=23 Weeks Payment 25=24 Weeks Payment 26=25 Weeks Payment 27=26 Weeks Payment 28=27 Weeks Payment 29=28 Weeks Payment 30=29 Weeks Payment 31=30 Weeks Bill Quote Link to comment Share on other sites More sharing options...
LizzyBee Posted November 4, 2011 Share Posted November 4, 2011 (edited) Duplicate. Edited November 8, 2011 by LizzyBee Quote Link to comment Share on other sites More sharing options...
Truscifi Posted November 4, 2011 Share Posted November 4, 2011 Because it says "about how many weeks" you are supposed to estimate. The way it is being taught in schools now is that you use mental math to figure it out - $366.38 (or whatever, I can't remember) is close to $360 which $12 goes into evenly for 30 weeks. Not the way I was taught, but it is what is being taught now. At least in ps here it is. Quote Link to comment Share on other sites More sharing options...
silliness7 Posted November 4, 2011 Share Posted November 4, 2011 I think I get what some are saying here. It'll take 31 payments but only 30 weeks. Quote Link to comment Share on other sites More sharing options...
elegantlion Posted November 4, 2011 Share Posted November 4, 2011 Ugh, I would have said 31, the question is vague. From the wording you could argue that she makes no payment, it only says she is "planning" on making weekly payments. Perhaps she missed a few weeks and the bike was repossessed. So she may never pay off the bike. The problem doesn't give us enough information to make a correct assessment. :tongue_smilie: Quote Link to comment Share on other sites More sharing options...
Supertechmom Posted November 4, 2011 Share Posted November 4, 2011 Was this question in a group of questions with directions?? I could see this being a group that said to use your estimating skills to find the answer. 30 would be right because you would estimate 360, divide by 12 and get 30. And I wouldn't think it was zero out payment 1 problem because that is usually referred to as a down payment with weekly payments afterward. The wording indicates that she is going to make payments every week until it's paid, not that she is going to put down money. If this was an estimation test or a question with directions that said to estimate,then I would say 31 is wrong. If it didn't give directions on how to solve and is not a specific chapter test that was on estimation, then I would say she is right because the bike can't be paid off in 30 weeks and rounding up is correct! But the word about screams estimation and 30 would be right because it takes about 30 weeks of $12.00 to pay it off. It's thirty weeks of 12 and chump change the next week. If the problem had asked how many weeks to pay it off, or how many payments would be needed that would be 31. But this one specifically wants to know how many 12.00 payments are needed. It bites. we hated those and still argue, fuss,and kick and scream over them as mine consider it trick wording. LOL! We struggled mightily with this and I had to do a lot of studying to figure out why this would be wrong. But I would call and find out why because estimation skills are very "in " right now and understanding how to solve those are important for test answers. Quote Link to comment Share on other sites More sharing options...
Guest submarines Posted November 4, 2011 Share Posted November 4, 2011 I think I get what some are saying here. It'll take 31 payments but only 30 weeks. True, but I don't think she was marked down because of that. She was marked down because she was supposed to estimate. :ack2: I really dislike poorly worded questions and the over-emphasis on estimation. Technically speaking, if they wanted an estimation (and not rounding to the nearest...) then 29, 30, and 31 should all be correct. Quote Link to comment Share on other sites More sharing options...
FaithManor Posted November 4, 2011 Share Posted November 4, 2011 Exactly. There would still be $6.38 left to pay and he wouldn't be able to pay for that until the next week, the 31st week. It reminds me of problems that say 9 students are being driven to the zoo. 4 fit in one car. How many cars do they need? 3, because 4 each in 2 cars makes only 8 students. Unless they are going to strap the left-over student to the roof of the car, they need another car for him to ride in! :D Oh yeah, don't you love real world math! :lol: I actually had a student in math class that I was subbing for get quite indignant with me that the third car (same problem you are describing) was not needed and his answer of 8 should be correct because the 9th person should sit on someone's lap! I pointed out that this would be against the law in this state and that it is important that our answers to any real world problem make logical, legal sense. His response, "Logic? This is math class. What does logic have to do with anything?" :glare: Sigh..sub-pay just isn't high enough! :D Faith Quote Link to comment Share on other sites More sharing options...
FaithManor Posted November 4, 2011 Share Posted November 4, 2011 True, but I don't think she was marked down because of that. She was marked down because she was supposed to estimate. :ack2: I really dislike poorly worded questions and the over-emphasis on estimation. Technically speaking, if they wanted an estimation (and not rounding to the nearest...) then 29, 30, and 31 should all be correct. GRRRR 31 is a perfectly legitimate estimation as well! Faith Quote Link to comment Share on other sites More sharing options...
amo_mea_filiis. Posted November 4, 2011 Author Share Posted November 4, 2011 Fill in the Blank Note: Your teacher will review your responses to questions 18–19 to ensure you receive proper credit for your answers. The above is what's written for the directions, so it doesn't specifically say to estimate. Quote Link to comment Share on other sites More sharing options...
EKS Posted November 4, 2011 Share Posted November 4, 2011 It's 30 weeks because presumably he paid $12 on the day he bought the bike and then the second $12 a week later. Quote Link to comment Share on other sites More sharing options...
Sun Posted November 4, 2011 Share Posted November 4, 2011 Because it says "about how many weeks" you are supposed to estimate. The way it is being taught in schools now is that you use mental math to figure it out - $366.38 (or whatever, I can't remember) is close to $360 which $12 goes into evenly for 30 weeks. Not the way I was taught, but it is what is being taught now. At least in ps here it is. Yes, but since $366.38 is clearly more than the $360 used in this estimate, it is also reasonable to add another payment on. In other words, if one does the estimate as Truscifi did, it's clear that it will take an extra payment beyond the 30. This is obvious without figuring an exact answer to 366.38/12 and then rounding it off, so I would absolutely argue it with the teacher. Quote Link to comment Share on other sites More sharing options...
EKS Posted November 4, 2011 Share Posted November 4, 2011 They are going to say: Payment 1=0 Weeks Payment 2=1 Week Payment 3=2 Weeks Payment 4=3 Weeks Payment 5=4 Weeks Payment 6=5 Weeks Payment 7=6 Weeks Payment 8=7 Weeks Payment 9=8 Weeks Payment 10=9 Weeks Payment 11=10 Weeks Payment 12=11 Weeks Payment 13=12 Weeks Payment 14=13 Weeks Payment 15=14 Weeks Payment 16=15 Weeks Payment 17=16 Weeks Payment 18=17 Weeks Payment 19=18 Weeks Payment 20=19 Weeks Payment 21=20 Weeks Payment 22=21 Weeks Payment 23=22 Weeks Payment 24=23 Weeks Payment 25=24 Weeks Payment 26=25 Weeks Payment 27=26 Weeks Payment 28=27 Weeks Payment 29=28 Weeks Payment 30=29 Weeks Payment 31=30 Weeks Bill This is correct. It's similar to the question of how many feet long is a fence with 31 fenceposts spaced 1 foot apart, it's 30 feet if you neglect the width of the posts themselves. Quote Link to comment Share on other sites More sharing options...
Spy Car Posted November 4, 2011 Share Posted November 4, 2011 Yes, but since $366.38 is clearly more than the $360 used in this estimate, it is also reasonable to add another payment on. In other words, if one does the estimate as Truscifi did, it's clear that it will take an extra payment beyond the 30. This is obvious without figuring an exact answer to 366.38/12 and then rounding it off, so I would absolutely argue it with the teacher. It will take 31 payments. No question about that. But it only takes 30 weeks to make 31 payments if you zero time out at the time of the first payment. See? Bill Quote Link to comment Share on other sites More sharing options...
Coffeemama Posted November 4, 2011 Share Posted November 4, 2011 Well, 30 weeks is on $360, so is the teacher going to pay the other $6.38? I think the word "about" is implying to round off to a more general number. 30 is much more general than 31, but I think it is poor wording. :iagree: Were there other problems involving rounding to the nearest 10? Quote Link to comment Share on other sites More sharing options...
Wendi Posted November 4, 2011 Share Posted November 4, 2011 I answered "30 weeks" because the question is "about how many weeks", which means they want you to estimate. If they said, "how many weeks", I'd say 31. Wendi Quote Link to comment Share on other sites More sharing options...
Night Elf Posted November 4, 2011 Share Posted November 4, 2011 Because it says "about how many weeks" you are supposed to estimate. The way it is being taught in schools now is that you use mental math to figure it out - $366.38 (or whatever, I can't remember) is close to $360 which $12 goes into evenly for 30 weeks. Not the way I was taught, but it is what is being taught now. At least in ps here it is. True, and now that I know it's Everyday Math, I wouldn't be surprised if the teacher doesn't mark it correct. This young girl will be penalized for looking at the answer from a real life application. Hopefully the teacher will realize that the student really thought about this problem and that either 30 or 31 should be considered valid answers. Unfortunately, I've known teachers who will stand by their original decision because the correct answer is reflective of the particular concept in the textbook. It just burns my bottom. Quote Link to comment Share on other sites More sharing options...
Sun Posted November 5, 2011 Share Posted November 5, 2011 (edited) It will take 31 payments. No question about that. But it only takes 30 weeks to make 31 payments if you zero time out at the time of the first payment. See? Bill I see that; I'm just not convinced that's what the teacher was thinking. In my experience, elementary-school math that says "about" is asking the child to estimate, so that's why I was responding to the estimation. I think it will be interesting to hear what the teacher's explanation of the problem is. Edited November 5, 2011 by Sun Quote Link to comment Share on other sites More sharing options...
The Governess Posted November 5, 2011 Share Posted November 5, 2011 When are the payments due? The first day of the week or the last day of the week? The assumption should be that payments are due at the end of the period unless other info is given. Under that assumption, 31 weeks is correct. Quote Link to comment Share on other sites More sharing options...
Firestar Academy Posted November 5, 2011 Share Posted November 5, 2011 True, but I don't think she was marked down because of that. She was marked down because she was supposed to estimate. :ack2: I really dislike poorly worded questions and the over-emphasis on estimation. Technically speaking, if they wanted an estimation (and not rounding to the nearest...) then 29, 30, and 31 should all be correct. :iagree::iagree: robin in nj Quote Link to comment Share on other sites More sharing options...
justasque Posted November 5, 2011 Share Posted November 5, 2011 I really dislike poorly worded questions and the over-emphasis on estimation. Technically speaking, if they wanted an estimation (and not rounding to the nearest...) then 29, 30, and 31 should all be correct. GRRRR 31 is a perfectly legitimate estimation as well!Faith Agree with both of the above. There are any number of ways to estimate. If the child showed work describing a reasonable method, then credit should be given. I understand that they want to teach "estimate" as a separate skill from "calculate", but I'm not convinced that the "about" in the question implied only estimation, as when you consider 1) the partial final payment, and 2) the whole first payment = week 0 issue, then 31 is "about" the number of weeks. Quote Link to comment Share on other sites More sharing options...
amo_mea_filiis. Posted November 7, 2011 Author Share Posted November 7, 2011 DD got a 76% on this math test! She got full credit (2pts) for this problem!!! Quote Link to comment Share on other sites More sharing options...
Guest submarines Posted November 7, 2011 Share Posted November 7, 2011 DD got a 76% on this math test! She got full credit (2pts) for this problem!!! That's awesome! Was it after you contacted the teacher? Did the teacher say anything? Quote Link to comment Share on other sites More sharing options...
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