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Eh. I must be thick as the answer is 86 (.8). How is the answer 6?
IMO it's 10-19 that screw it up, especially 11 and 12, after that you've got proper sets twenty thirty etc, why do we have eleven instead of "onety one" or "oneteen"?
A man after my own heart 😀
It's amazing how many of these [i]universally-accepted-yet-weird[/i] things you notice when you have kids and they start asking "Why?" 😀
English is just as fickle: e.g. drink, drunk, drank.. wtf?
Really odd when I thunk about it properly.
I was Mr thicky McThick at Maths but having read the posts even I get it. OP it's not hard, really it isnt.
After looking at the first page of Mumsnet there I see where they were going with this now.
10. There are always 10 tenths of a whole whether the whole be 15 or 370. Each tenth is 1.5.
The "logic" here is you have "something", you divide it by ten, how many parts do you have? Ten!
It's flawed logic though. If your "whole" is six oranges, you'd end up with ten tenths of six oranges, which is nonsensical.
The thread says it's a badly worded question. It's not, it's just out of context. The kid learns about units all day - hundreds, tens, units, tenths, hundredths - then comes home and goes "mum, how many tenths are there in 1.5?", mum then posts to Mumsnet and chaos ensues because they've not been given sufficient information to solve the question in the manner being tested for.
Orbital mechanics (aka dead hard sums aka maths) allows us to plan the landing of a probe on a comet a bazillion miles away
well that's sort of my job, and my answer is 6
if you have difficulty with hundreds tens and units don't look at [url= http://www.bbc.co.uk/schools/gcsebitesize/maths/statistics/representingdata2rev4.shtml ]leaf diagrams[/url]
And the truth is revealed.
That question is from a different sheet.
I was right about moving goalposts. They're two different examples from two different question sheets (potentially) testing two different things. No wonder it ran to a thousand posts.
Mumsnet... It's flawed logic though
Quite!
(Maybe that could be their tagline?)
Eh. I must be thick as the answer is 86 (.8). How is the answer 6?
868
8 'hundreds'
6 'tens'
8 'units'
DONK I just tried
[img] 
[/img]
[s]mum[/s] Hora then posts to Mumsnet and chaos ensues
if you have difficulty with hundreds tens and units don't look at leaf diagrams
Easy enough to understand, I just wonder [i]why[/i] you would want to set your data out like that?
It's a histogram for people without Excel. 🙂
(and better than a histogram in one respect, as it leaves the original data intact).
That Mumsnet page just keeps on giving. "I have a maths degree!" - yes, but this is Key Stage 2. Your average junior school kid isn't going to be doing differential calculus, they're going to be learning what it means when you move a digit one to the left.
"I have a maths degree!"
Like the pilots and aircraft engineers that show up on the airplane/conveyor belt thread.. and get it wrong. 😀
My wife has a Master Degree in how the under 7's learn mathematical concepts.
It's sometimes quite counter-intuitive for those of us who already understand it.
Gods, someone's talking about Base 1 now. WTF is base 1? A numerical system where a digit can have [i]one[/i] value?
"Count after me, children:
1,
11,
111,
1111,
..."
"Miss, what's 1 minus 1?"
"Don't be clever, Henry."
Its like these questions that are posed in facebook which go along the lines of 1 x 2 - 3 + 4 x 6 = ??? Which are nonsense without brackets.
Firstly:
It's like the questions which are posted on Facebook, which go along the lines of 1 x 2 - 3 + 4 x 6 = ? , which are nonsense without brackets.
No brackets, not nonsense:
1 x 2 - 3 + 4 x 6 = 2 - 3 + 24 = 23
On the original question, division by ten and "how many tens?" on a place value exercise are very different.
[i] A numerical system where a digit can have one value? [/i]
I'm all for base 0.
It's a histogram for people without Excel.
My first thought was why bother doing it like that, when you could just use a spreadsheet 🙂
TBH, I think I'd rather my kids learned to use a spreadsheet than learning about leaf diagrams, seems more useful. Although I'm willing to admit I could be missing something, do these diagrams lead on to something more interesting?
I'm a qualified primary school teacher, who now teaches GCSE maths and A level physics. Am I correct in thinking I'll get annoyed if I look at the Mumsnet thead?
Unless you're dealing in something other than decimal there is no way while I've got a hole in my arse that the correct answer to "how many tenths are there in 1.5" is "10."
I think when teaching kids they just leave out a bit of context that we as grown ups need due to our extra knowledge of division. The question would be better phrased as...
"How many tenths [b][i]of 1.5[/i][/b] are there in 1.5?"
That makes the answer obviously 10. They are trying to test that the puplil knows that "tenths" = spilt into ten lumps.
A similar question could be...
"How many eighths (of 763) are there in 763?" with the answer being 8.
Its not intuative but then I'm not 8. I may have to take a course when my kids are old enough to go to school!
I think I'd rather my kids learned to use a spreadsheet than learning about leaf diagrams
It's not one or the other.
(Although, I'd never even heard of a stem and leaf plot until I taught it for the first time, and I'm still non-the-wiser on when they'd be used. They do make it easier to find the mode and median values when working by hand.)
No brackets, not nonsense:
Again, it is a nonsensical without context. You're correct according to operator precedence, but would primary school children be learning BODMAS?
That's the mistake some of the Mumsnet lot are making, all degrees and no common sense.
would primary school children be learning BODMAS?
Yes.
Fair enough then (-: It was actually a genuine question, you answered before I edited the post to say so.
"How many eighths (of 763) are there in 763?" with the answer being 8.
I find it hard to believe that this is the sort of question that would be asked in a school maths lesson. A Christmas cracker, maybe.
It's not one or the other.(Although, I'd never even heard of a stem and leaf plot until I taught it for the first time, and I'm still non-the-wiser on when they'd be used. They do make it easier to find the mode and median values when working by hand.)
I appreciate you could teach both, but I'm still thinking that leaf diagrams are a bit of a waste of time, and given that time is limited it would be better spent on learning how to get Excel to do the hard work for you. (With appropriate theory taught first of course, not just plugging the numbers in and getting the answer!)
ten tenths of six oranges
BOOM!
I teach stem and leaf diagrams because they're on the exam, not because I think they're useful 🙂
"How many tenths of 1.5 are there in 1.5?"That makes the answer obviously 10.
No that makes it WAAAY less obvious.
a "tenth of 1.5" is 0.15
So "How many tenths of 1.5 are there in 1.5?" means "How many 0.15 are there in 1.5"
They are trying to test that the puplil knows that "tenths" = spilt into ten lumps.
They're not. Mumsnet has it wrong.
They are either testing division skills (possibly) or they are testing knowledge about place values (most likely).
If they wanted to test splitting whole things into ten parts as the definition of "tenth" then the question would have been "What is a tenth of 1.5?"
I appreciate you could teach both, but I'm still thinking that leaf diagrams are a bit of a waste of time, and given that time is limited it would be better spent on learning how to get Excel to do the hard work for you.
Same argument as [i]"Why teach kids to multiply or divide when in reality they'll just use a calculator."[/i]
Same argument as "Why teach kids to multiply or divide when in reality they'll just use a calculator."
Not sure it is, a leaf diagram seems to have little or no use in real life, beyond passing your GCSE maths exam.
Whereas long division... 😉
Not sure it is, a leaf diagram seems to have little or no use in real life, beyond passing your GCSE maths exam.
They make mode and median a bit more obvious, when you're learning what they are.
Mrs just told me about leaf diagrams I [s]never did[/s] don't remember doing them at GCSE/A level.
Back to an earlier point maths is supposed to involve accepted standards so everyone* knows what you are talking about, hence precedence and naming numbers correctly. twentysix hundred should be fairly easy for most to figure out but threesixty, seventwenty and teneighty, which I'm sure most of the people here could guess at, may not mean a lot to a doddery old maths teacher.
....I think
*or atleast everyone who knows/remembers the rules
They make mode and median a bit more obvious, when you're learning what they are.
Suppose so 😕
Wonder if my kids will learn about them? Thanks to the wonders of STW I'm now perfectly positioned to explain it, even in base 1 if need be.
Back to an earlier point maths is supposed to involve accepted standards so everyone* knows what you are talking about, hence precedence and naming numbers correctly. twentysix hundred should be fairly easy for most to figure out but threesixty, seventwenty and teneighty, which I'm sure most of the people here could guess at, may not mean a lot to a doddery old maths teacher.
I think you're mixing up two concepts - mathematical rules (BODMAS and the like), and mathematical culture (how you talk about maths). The first is universal, the second quite clearly isn't, with some variation even within a country.
Incidentally..
I get the feeling a lot of people on this thread haven't realised that maths teaching has moved on since they were kids!
Lattice Multiplication was a bit of a revelation for me when I found it recently during an idle browse of [url= http://www.khanacademy.org ]Khan Academy[/url].
I was never taught it in school (that I remember), but it seems like a good method of multiplying very large numbers.
Do schools give out to parents the syllabus or teaching material? As has been said, it's all about context, that needs to be conveyed to the parents. It strikes me that when our little girl goes to school there'll be a whole lot of re-learning to be done!
Cheers,
Jamie
Lattice Multiplication
Just googled that as I've never come across it before. Unless I'm misunderstanding what I'm seeing, it's just long multiplication, only with more writing. I guess how I can see how it might simplify multiplication but at the expense of both brevity and comprehension.
That is to say, you can see the logic in long multiplication fairly readily, you're multiplying by each digit in turn, adjusting for units, and adding them all up. Lattice multiplication looks like a magic trick.
Yep. Try it with a few worked examples though Cougar - bundling the multiply and addition steps together turns it into a much more mechanical task and makes it a lot simpler to do.
The logic [i]is[/i] still there - it just takes a bit to adjust your brain to the "columns" being on the diagonals.
So "How many tenths of 1.5 are there in 1.5?" means "How many 0.15 are there in 1.5"
And guess what, there are 10 0.15s in 1.5. So the answer is 10. The given answer.
They are testing you know what a tenth, or an eighth or a fith is. The important bit of the question is the "how many tenths" bit. The rest of the question is irelevant, it could be 1.5 or cake or horses or overweight mountain bikers, it doesn't matter, if you split something into tenths there will always be 10 bits.
You are confusing yourself with your ability to work out what 1 tenth of 1.5 is (and one tenth of 1 if you want to answer 15).
They are testing you know what a tenth, or an eighth or a fith is.
I'm [i]really[/i] not convinced they were.
Certainly not in the context of a set of questions about hundreds, tens, and units, (and tenths, hundreths etc).
That just seems to be what someone on Mumsnet decided.
You are confusing yourself with your ability to work out what 1 tenth of 1.5 is (and one tenth of 1 if you want to answer 15).
Nope.
The answer I expected was 5
e.g. simply the contents of the "tenths" column