Fear and Loathing in Grade 3 Math Class

October 29, 2015

Hellooo My Little Luvvies,

So you are in Grade 3. You are asked to do this: Use the repeated multiplication strategy to solve: 5 x 3. Here’s your answer:

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Firstly, give the kid a cigar. According to The Telegraph, UK the kid is only in Grade 3 and can read: repeated multiplication strategy without their head exploding. Secondly, this kid understands the question.

5 x 3 = 5 + 5 + 5  except, according to the teacher, this answer is wrong.

3 + 3 + 3 + 3 + 3

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According to The Telegraph : The National Council of Teachers of Mathematics (NCTM) in the US defended how the paper was marked, saying it gives students a better understanding of the problems they are solving.

Of course, the NCTM is suggesting:

5 x 3 = 5 times 3 = 3 + 3 + 3 + 3 + 3

5 x X = 5 times X = X + X + X + X + X

X x 3 = ?

X x 3 = X times 3 = 3 times X = X + X + X

Mathematicians have to think like this! They must be nibble. Mathematicians must think for themselves.

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Too many kids hate maths due to FEAR or BOREDOM. How much would you hate maths if you got correct answers marked WRONG?

And how much would you FEAR the next maths test?

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Needless to say, I’m with Bart. Math teachers should not mark right answers wrong for any reason. More reasons why kids hate maths here:  BEWARE OF MATHS FUNDAMENTALISTS

Cheerio for now

January 15, 2014

This Hollywood Cliché can Kill

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10 Movie Cliches Debunked with Maths

February 4, 2011

February 4, 2011

6. Goofy Graphs

October 12, 2010

When graphs are pretty but provide no real information or are misleading.

Graphs frequently appear in the media with no scales, odd scales or totally misleading scales.

This first graph from the Financial Review: Smart Investor magazine ( Oct 2010) has no scale. You could just scribble a line and call it a graph ( See Above) !!!! Then add a number at the end point to make it look real!

Why use a graph? It’s an investment ad selling an investment product.

The second graph shows that the recent Global Financial Crisis was not so bad. Now look at the y-scale. It’s logarithmic.

Some more useful graphs at Bored Panda Blog:

7. Crystal Ball Maths

October 12, 2010

Extrapolation.

Extending a graph or equation beyond defined limits.

Extrapolation is in your head. Just because you have a graph and, maybe, even a formula it doesn’t mean you know all the variables. Put simply, you cannot just extend a graph into the future. You may be right or……. Great Balls of Fire! You could be wrong!

Here is an extract of an article by Jeremy Laurance in The Independent, UK, on 27th April, 2009:

‘At its worst, it could have a devastating global impact, greater than a terrorist attack, nuclear accident or environmental disaster. The World Health Organisation estimates that a mild pandemic could cause up to 7.5 million deaths.’

If you look at the current count as of 11th October 2011 verified World Wide deaths from Swine Flu are 14, 337. (See Swine Flu Count)

Any death is tragic but according to WHO in a normal year, flu kills 12,000 to 20,000 mainly elderly people in Britain and 250,000 around the world.

For more statistics : swine flu mathspig

9. We’re All Gonna Die!!!!!!!

October 12, 2010

Statistics

Statistics apply to Groups not Individuals

or Why Death Rates are Over-Rated!!!

We’re All Gonna die!!!  Well, um, this statement is true. The morbidity rate for humans is still 100%. Hopefully, you will be happy, healthy and 110 years old before such statistics begin to worry you.

Newspapers often run statistics stating that your chance of being killed by a shark is 1 in 271,257 as shown. It’s NOT.

Firstly, you know this statistic is a bit dodgy. If you do not go into the water ever you will never be eaten by a shark. You chance of being shark bait is a BIG 0.

Secondly, these statistics apply to groups not to the individual. In every 271,257 Australians 1 MIGHT be eaten by a shark. In 251, 257 surfers the numbers eaten by a shark would be MUCH greater.

Finally, these numbers still seem high. What?  77 people are killed by sharks in Australia annually. NO. These are statistics over a lifetime. 80 years, say. Less than 1 Aussie a year is killed by sharks on average but just because one surfer has died you cannot say ‘Great! The sharks have reached their annual quota I can go back in the water.’

Statistics can NEVER tell you WHAT might happen to you!

It’s a GROUP THING. All you can learn from these statistics are the  exit-the-earth probabilities for Australians that, mostly, we don’t get to choose.

10. Dumb Media Maths

October 12, 2010

Statistics

When the numbers are totally fake but no one checks!!!!

The biggest mistake made by journalists in the media is NOT QUESTIONING the numbers or validating the source. Rubbish statistics work their way into the media and become the gospel according to everyone. Sometimes, media maths seems to be written by dummies for dummies.

In an excellent article Numbers UP: Truth About Statistics ( The Independent, UK, 9th April, 2008) Simon Usborne states ‘ Flicking through a day’s newspapers often feels like tackling a numerical assault course.’ He quotes some alarming headlines form the previous day including “Ninety-six per cent of children in European orphanages are not orphans”. “In the UK we throw away 4.4 million apples a year”.

My favourite, however, is :

“Falling coconuts kill 150 people a year”

In 2002, in an article about the uprooting of coconut trees by lawsuit-wary Australian officials, the Daily Telegraph reported: “Coconuts… kill about 150 people worldwide each year, making them more dangerous than sharks.”

No source has yet been found confirming this statistic.

Similarly,

Researchers at the University of Pennsylvania decided to search for the source of the statistic that insisted you should drink 8 glasses of water a day. Their conclusion: “It is unclear where this recommendation came from.” In other words, they could not find any study to support the “eight glasses” claim.

So when you are drinking those 8 glasses of water a day you better look up incase you’re hit on the head by a coconut!!!!!!!

Do economists study voodoo or maths?

September 17, 2010

I work in the media. I’ve been a journalist for over 25 years and I am constantly stumbling over BAD MATHS in the MEDIA.

Some of the BIGGEST MATHS BLOOPERS involve economists. Do economists study maths or rely on voodoo? Or do they deliberately set out to mislead the public? You decide.

In the How big is a Trillion? post (above), I highlighted the order of magnitude of calculations involving national economies. In this MATHS BLOOPERS MADE BY ECONOMISTS post, I will introduce you to the concept of UNCERTAINTY and how it makes a non-sense of some economic calculations.

Any  measurement carries an uncertainty with it.

If you were measuring a length of wood you could write down the measurement as:

103 cm

103.0001 cm

105.000137 cm

Unless you are using an electron microscope you cannot measure a length of wood to one millionth of a cm.

Meanwhile, the amount of money you have in your wallet is an ESTIMATE. You may not know how much you have to the nearest cent. But you will most likely know round about how much you have. Economists use estimates in their calculations. But you will appreciate that estimates must have an uncertainty attached.

You will find  a very good explanation of UNCERTAINTY

Now let’s look at some recent calculations by our Department of TREASURY and FINANCE.

You might think that TREASURY involves public servants shovelling our taxes into Scrooge McDuck money vats or bureaucrats crowing ‘pieces of eight’ as they run their hands through Pirates-of-the-Caribbean chests of loot but that is not the case, although I do understand they have some lovely desks. TREASURY does all the fiddly calculations to do with the economy.

Recently during the elections in Australia, Treasury calculated that Political Party A (I’m not concerned about the politics here. Just the maths. You can check on the numbers @ \$11 Billion Black Hole), who claimed their budget savings estimates to be  \$11.5 billion were wrong. This may indeed be true, but you cannot correct bad maths with more bad maths.

TREASURY looked at the figures and came up with savings estimates for Political Party A of between \$0.9 to \$4.5 billion. Is this good maths? Let’s see.

Treasury’s calculations begin at, say, \$1 billion and go up to \$4.5 billion. That’s a range of 450%.

Estimating budgets is not an exact science. But to produce calculations with an uncertainty of 66% is RUBBISH MATHS!!!!!!! It would be like someone measuring your neck at 27 cm plus or minus 18 cm!!!!!!

Moreover, if the calculations are complicated then the uncertainty INCREASES at every step!!!!!!

Meanwhile, TREASURY are the folk who do all the calculations for our economy. God help us!!!!!

So think of a number between 1 and 10 now multiply it by a billion. You can get a job in Treasury.

The 10 Dumbest Maths Questions

March 21, 2010

This post could be called the 10 Most Annoying Maths Questions. It began when Sarah Ebner, who runs the fabulous Edu Blog for the Times (UK) Schoolgate asked me to comment on her daughter’s maths homework.

Here is the question:

This week we have been working on addition and subtraction linked to money. The children have been using skills relating to mental strategies such as bridging through a multiple of 10, number bonds, partitioning, doubling and near doubles, counting on or back in 10s, using what they know to look at patterns or use the inverse, using imaginary number lines or 100 square in their heads. They have also been using the idea of the difference when doing some subtraction sums or when giving change

Using the appropriate strategies, complete the attached worksheet. Show your workings. Buying a balloon. Lolla bought a balloon at the circus. She gave the clown six coins to pay for it.

What could Lolla have paid for the balloon? Which of your answers seems a reasonable amount to pay for a balloon?

Key questions:

What is the largest amount of money we could make? What is the smallest amount of money we could make? How will we know when we have all the possibilities?”

Now keep in mind this HOMEWORK has been set for an 8 year old. The complexity of this maths is ASTOUNDING, obviously, for an 8 year old. This question fits the heading ‘Permutations & Combinations’ which introduces Statistics. The language is over-the-top. It is in Australia too. Why can’t kids just DO maths? I was helping my 10 year old neighbour do his maths homework on Thursday. He was doing short division. ‘You have to know the algorithm’ he explained. “You mean you have to know the way to do the maths?’ I asked. His 8 year old sister did a pig drawing for me. I think she’s captured the moment, really without prompting.

PARENTS who do not do maths must feel totally intimidated. As an ex-maths teacher married to an engineer our kids were not blessed either. We tried, on occasion, to help them out. But it was TOO MUCH information. It might explain why both of my children grew up to be arty. One of my kids was bored witless in maths and would fall asleep on his notes. The other one did maths like SUDOKU to fill in time between art classes. Their experience, in part, is why I’ve created Mathspig. They’re not alone. Australian students are dropping advanced maths in droves. The statistic shown was published in The Australian yesterday (20th March, 2010)

I went and read a number of maths books lying around the house – collecting dust – and I found there was a real pattern to Dumb Questions.

When I returned to maths – as a hobby, always lerved it – after 25 years in the media I found texts books often read like THE ANCIENT RED SEA SCROLLS. What area does a goat graze???? A GOAT!!! Why not ‘what area does your computer mouse need to move at different lengths?’ Good maths students will tackle anything. Teachers face greater challenges. This blog is aimed at finding ways of grabbing the attention of ALL students.

Please send me any DUMB MATHS QUESTIONS you stumble across and I might give an award at the end of the year to the dumbest. The questions below are from a Year 7 TEXT book unless specified. It was quite a good text but well…..

Here are the 10 Dumbest Maths Questions;

1.SO FAKE

These are the questions where maths teachers (Text book writers are usually maths teachers) want to say ‘Look! See maths is important. You can use this particular maths to solve real problems. But the questions are so FAKE they’re laughable. Some boil down to the three men walked into a bar type model … others are just weird. Check out the Names in Q (below) and the Year 12 Q. What is the likelihood of hitting the bird? -Um, absurd!!!!!!

2. ONLY AN IDIOT

Once again trying to show students that maths is useful questions are asked that only an idiot would try to solve using maths.

IN the Year 11 Q2  (Below) if you had any relationship with a sheep or a goat – I’m thinking goat farmer – you don’t calculate the area grazed. You move the goat. In Q1 how could your friend remember all of those details, but forget the actual number of your house!!!!!!

3. THE MORAL TO THIS MATHS

In the first question check out the punishment for not doing maths!! That’s about as subtle as being hit on the head with a Maths Landing Vehicle.

In the second question the mathematicians die!!!!! Mind you, the idea might cheer up the class. look how much homeowrk the kid does in the last Q? Year 7.

4.MAKE THE MATHS WAY MORE COMPLICATED

In the first Year 11 Q you do not use matrices to score cricket statistics. In the second Q if you want to know the names of your friends, um, ask them.

5. REIGN OF TERROR

or Fear and Loathing in the Loungeroom. This is when the maths set is way beyond the resources or standard of the students involved. If these questions are then sent home as homework – as with the Q that started this whole discussion – then the pain is transferred others. Sometimes you suspect that teachers offload the questions they can’t answer to parents!!!! Here are some more. The Q1  is doable but it will be hours of fun and games for all the family. Q2, um, Wha?

6. CLUELESS

The students are studying fractions, say. Then they are given a task that involves maths they have not learnt yet. The problem is that the question looks reasonable but isn’t. These sorts of questions produce the whining lament of young students … ‘I can’t do maths!!!’

7. WE ARE FUNNY GUYS. WE MATHEMATICIANS. HA! HA!

When maths teachers make jokes they are often lame. Check out the Question below. It’s just bad PR. Who would want to grow up to be such a nerd.

8. IMPOSSIBLE

Either the question is impossible to solve. These often come from typos like ‘find the square root -4’ in Year 8. Or the question is just all wrong. Could you cut a cloth into 1mm strips…. without a laser cutter?

9. WHY BOTHER?

There is no point to doing the question. Who would count the legs to find out how many beetles are involved? So why do it?

You could go to all the trouble to work out the surface area of your dog and then calculate how many hairs Rufus had, but why? Is Rufus worried he’s going bald?

10. THERE’S NO ANSWER YOU B*&#*#!S

This has made me rethink mathspig. I’ll add more answers. There is nothing more frustrating that doing all the hard work and there is no answer at the back of the book. You want to throw the book at them. The following is a Year 12 Q but, alas, no answers at the back of the book.