April 9, 2013

January 15, 2013

# Weird Maths Activity

## You choose!!!

Subject A

Subject B

Subject C

Subject D

Subject E

Subject F

Subject G

Subject H

Subject I

Subject J

Subject K

Subject L

This is a maths teacher,
However, you might understand why students suspect he falls in the other category!!!!!!

A. Teacher, B. Teacher, C. Jeffery Dahmer, D. Teacher, EDr Harold Shipman, F. Charles Manson, G. Albert Fish, H. Joseph Harwell, I. Teacher, J. Teacher, K. Teacher.

*All the teacher photos come from education archives but will be removed on request.

May 4, 2012

## The Hunger Games Maths

April 11, 2012

### The Hunger Games is about MATHS. Here are some interesting Hunger Game statistics.

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### 18 year olds …….. 7 slips

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July 4, 2011

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April 20, 2011

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April 8, 2011

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# π

## Cool Formula For Calculating Skyscraper Sway

March 21, 2011

The world is in turmoil mathspigs with earthquakes, tsunamis and nuclear power plant meltdown worries. It is the job of engineers to calculate and incorporate – as far as possible- safety margins into the structures of buildings, dams and power plants. Observers have noted that the skyscrapers in Fukushima wobbled during the recent 8.9 magnitude earthquake in Japan.

This is intentional, as rigid structures can snap in strong winds or during earthquakes.

But the maths used to calculate SKYSCRAPER SWAY is straightforward.

The Earthquake Engineering website offers a simple explanation.

Short, rigid buildings are damaged in earthquakes because they shake very fast. 10 story buildings have a period of oscillation of about 1 second the same as the earthquake pulse. This is VERY dangerous.

Tall, flexible buildings can withstand an earthquake because they can sway. They are like a very large, slow moving tuning fork. If they are TOO RIGID they snap. If they are too flexible the people on the 100th floor would be throw all over the place.

The 59-story steel-construction Citicorp Centre, NY (pictured) has an oscillation time of 6.7 seconds. Details Google Books.

The 102-story brick clad Empire State Empire Building sways about 8cm ( 3 inches) whereas the 110-story steel -mesh World Trades Centre Towers, NY, before they collapsed swayed over 1 m ( 3 ft 5 inches).

One more thing. You want buildings to have springy foundations so they don’t snap at the base and fall over.

# Earthquake Engineering

The idea is not to strengthen the building, but to reduce the earthquake generated seismic forces acting upon it. This can be done in 3 ways.

## 1. Base Isolation. Rubber pads or Rollers. Are used so the base does not feel the full shake or jump off foundations.

Details Base Isolation Specialists

## 2. Shock absorbers or dampers are added to the structure to dissipate the seismic shock.

Details Damper Supplier

## 3. Active Tuned Mass Dampers use a computer controlled counter moving weight to actively move against the building sway.

The 508m (1,667-foot) Taipei 101 Tower would sway back and forth up to 60cm (2 feet) each way within five seconds. This according to Wired magazine is highly barfogenic or spewdacious, perhaps, in Aussieland.

The Taipei 101 engineers included a 662 tonne (730-ton) counter giant pendulum to act as a counter weight.Some buildings use a big block of concrete.

It is pushed in the opposite direction to the building sway to dampen the oscillation.

# Take 1:

Wired magazine includes the equation for Skyscraper Sway acceleration (See definition of terms @ Wired link):

But I’m going to use a student friendly equation from Wind Engineering for Large Structures.

Mathspigs, you can just look at this equation and see how to change it to make a building EARTHQUAKE SAFE. Keep in mind that k, the stiffness constant actually decreases for taller buildings.

Imagine you are designing a building to withstand the 8.9 magnitude earthquake. You have already added base isolation. Now you have three options to work with: building mass (m), damping constant (c) and stiffness constant (k). Remember the earthquake force is constant. If you change just the stiffness of the building (k) what happens to the distance of sway(x)?

Engineers have to come up with the optimum design for the strongest structure with least acceleration (but enough building mass for strength), greatest damping and least sway at the lowest cost.

# Take 2:

Structural Engineer Ron Klemencic explained on the Discover News that a simple rule of thumb for calculating skyscraper sway was to simply divide the buildings height in by 500 because the building codes demand the building fit a 1:500 sway ratio.

The tallest building in the world at 2,716 feet (828m), the Burj Khalifa, Dubai, would sway back and forth about 5.5 feet or 1.7 m.

Ahhhhhhhhh!  But you would have to drag Mathspig onto the 168th floor screaming.

But mathspigs you can work out the sway on the top ten tall buildings in the world.

## 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.

## 10 You can out run a lava flow

November 16, 2009

Every volcano disaster movie from Volcano (1997) with Tommy Lee Jones to Dante’s Peak (1997) with Pierce Brosnan someone somewhere tries to out run a lava flow. Is this possible?

The answer is maybe. You will find everything you want to know about lava flows @ http://volcano.oregonstate.edu/

On January 10,1977, at Nyiragongo lava sprang from the sides of the volcano moving at speeds up to 40 miles per hour (60 km/hr). About 70 people were killed.

Measuring the temperature of lava. Photograph by R.L. Christiansen, U.S. Geological Survey, January 9, 1973.
The fastest Lava flows recorded were in Hawaiiin 1950 when Mauna Loa erupted. The lava traveled at 6 miles (10 kilometers) per hour through thick forest. But once the lava flows became established and good channels developed, the lava in the channels was flowing at up to 60 km/hour (97 kph).

Speed of average sprinter = 19 – 24 kph

Can you out run lava?

Work it out mathspigs. You are 300m ahead of the lava flow and you need to get up a hill to escape, which is 1000m away. The lava is flowing at 30 kph and you are running at 18 kph.

Will you make it??????