Archive for the ‘Logarithms’ Category



August 4, 2020


DAY 50 Covid-19 …. some STATS

March 13, 2020

Covid-19 stats update here.

World deaths stats here

Even if the entire pop. of the world was infected the important statistic is the death rate. On 3 MAR WHO put the Covid-19 death rate at 3.4% of those infected by the virus.

Note: Covid-19 logo frm Pngtree


Maths Cure for Wolverine

July 25, 2013

Jackie from Straight Ace Learning ( Maths & Movies ) asked Mathspig to come up with a formula for Wolverines super fast super healing powers. He can regenerate or heal in 5 seconds. In the latest Wolverine Movie he becomes mortal ….

Wolverine Facts:

No. Cells in a human/X-man Body

= 75 trillion cells  = 75 x 1012

(Mid-point of 60-90 trillion cells cited on the fab AskaBiologist website)

Imagine Wolverine is slashed/shot/wounded in the abdomen.

Human Trunk

= 44% of the body.

(See Body Segment Data here)

Estimate Cell Damage

= 1/4 of trunk = 44/4 = 11% = 0.11

Number Cells Damaged

= 75 x 1012 x 0.11 = 8.25 x 1012

You will need your Web 2 Scientific Calculator (See diag below).

W 1

W 2

W 3

This is what the calculation looks like on the WEB 2 Scientific Calculator. 





W 4 calcs





October 21, 2011

It’s not often that we have British actor Jude Law ( above) explaining maths to us, but in the new Hollywood film CONTAGION

he demonstrates how quickly a deadly virus could spread … (1.17 point on trailer)



Jude Law plays the colourful blogger Alan Krumwiede. Gwyneth Paltrow’s character dies and Matt Damon tries to save his daughter. (See pics)









Krumwiede says ‘ On day one there were 2 people, then 4, then 16 … in three months it’s a billion. That’s where we’re heading.’ Is he right?



.Now this bug is highly contagious, but Krumweide’s estimates start high and end low. In the film he says the number of infected people will grow according to the series 2, 4, 16, 256 and then a number Mathspig,um, missed. (I was munching popcorn.)

This is wrong. According to this progression by Day 3 each person must go out an infect 16 other people. By Day 4 they must infect 256 people each. By Day 5 they must infect 65,536 people each. That is a BIG cough.

Then he claims that in 3 months or 90 days 1 billion people will be infected. That’s so sweet. If the Gweny bug was so highly  contagious the human race wouldn’t last that long. Oddly, however, this number has synergy with the TWILIGHT VAMPIRES.

Even if each germ-riddled person infected only 1 other healthy person each day, this is how long we would last:

You may need to use the WEB 2.0 calculator to solve this problem.




Not everyone on earth would die, of course. As the numbers drop so do the infection rates. Meanwhile, some people in remote areas would not get infected and some people would have immunity and that’s when the plot gets hot, HOT, HOT!!


12 minute Maths Guru

July 4, 2011

Meet Salman Khan. He has put free maths on-line.

This article on Salman appeared in The Sunday Times, UK, 12 JUN 2011.

Salman, 28, started putting tutes online for his 12-year-old niece, Nadia, and things grew. So far the Kahn Academy’s claim to fame are:

* Over 2,400 videos including hundreds and hundreds of 12-minute maths tutes

* Over 63,000,000 lessons delivered.

* Bill Gates kids use the site.

* A staff of 1 with funding from The Bill and Melinda Gates Foundation.

* Tutes on Biology, Chemistry and Physics too.

You can look up the maths tutes by topic @ The Khan Academy.

Or search topics on Youtube eg. Introduction to Conics Khan

Why Does Mathspig like The Kahn Academy? Because it’s:

1. Free.

2. Quick

3. Clear

4. Low-key







Salman gives digital chalk-and-talk tutes like a teacher. He hand draws the equations and graphs. He uses a calculator from time to time, but he tends not to use whizz bang spreadsheet graphs or perfectly presented textbook equations. It’s a bit wobbly and it’s all coming from Salman’s head.

And students like this approach. It makes maths look do-able.

Go, Salman.

Mathspig thinks you are just GORGEOUS!!!!!!!!!

 Australia’s Year 7 – 12 Maths Curriculum is already on-line and free, funded by McDonald’s. See What are maths teachers for, sir?

The tutes on Maths Online are produced by Aussie Maths teachers and they are very good. Mathspig, of course, imagined the quadratic function tutes might look something like this:


Easter Egg Maths

April 20, 2011

Mathspig can’t stop thinking about EASTER EGGS.


How do you do you  graph  an Easter Egg?


Fortunately, Jurgen Koller @ the fab mathematische-basteleien website has already solved the problem.


Start with an Oval.


To change it to an egg shape multiply  y or y² by  t(x), so that y becomes larger on the right side of the y-axis and smaller on the left side.

y(x=0) must not be changed. 


The equation of the ellipse:


e.g. x²/9+y²/4=1






Three examples:


Now plot in chocolate paint and eat graph. Yum!!!

According to Jurgen Koller, Don M. Jacobs, M.D, Daly City, USA developed a nice egg shape by changing the circle equation x²+y²=1 a little: x² + [1.4^x*1.6y]² = 1.

The egg equation is an exponential equation of type t3 above. This shows this conversion:



Thanks, Jurgen. I wonder if he’s an Egghead!!!!!!


Twilight Maths II: Will Vampires rule the world?

January 29, 2010

In Stephanie Meyer’s the Twilight series there are good Vampires and Bad Vampires. Edward Cullen and the other Vampires in the Cullen Covern are ethical Vampires. (See earlier post: Fang it to me! : Twilight Maths) The only eat animal blood. Edward falls in love with Bella a human. The baddie Vampires are James, Laurent (pictured) and Victoria.

Twilight Vampires, as with all vampires, can turn a human into a vampire by biting them. IN the Twilight mythology a vampire injects a venom into their victim and, depending on how much venom is injected the victim will turn into vampire in 3 – 5 days.

Vampires who drink human blood have red eyes. So freshly made vampires have bright red eyes due to the human blood already in their veins. Vampires who drink animal blood have yellow eyes.

How long would it take one Vampire, say James, to turn the whole population of the earth into vampires? We can work it out, mathspigs.

On the first night James goes out and bites a human. Now there are two vampires. Each night the vampires go out their numbers double.


These calculations were updated for clarity on 21 OCT 2011 after I’d worked on my JUDE LAW CAN’T DO MATHS post. Now in the Twilight Series it takes 3 days for a  human to turn into a vampire. So we will assume that James and his rapidly growing covern go out every 3rd night to feast on human blood.

How many days will it take one bad Twilight vampire to take over the world (Population 6.8 Billion. See World Population Clock US Census Bureau ) ? You work it out. But here is a hint.

I suspect the Cullen Family are smart vampires because they only drink animal blood.
Unless, animals also turn into vampires and we are over run by vampire squirrels, vampire poodles, vampire canaries and more.


Why you have to watch those tricky economists!!!!!

July 29, 2009

holdworld_tns  MATHS IN THE REAL WORLD

which is everywhere!!!! log graph 2 Correction

Economists may not set out to mislead the public, but they do produce graphs that can easily be misread. Here is a graph from AMP (again) published in THE  AUSTRALIAN  on 29/7/09 (p12 . Wealth supplement.).

Have a look at the graph. What’s wrong with it?????????????

Mathspig Maths Mystery Box 1 graphFirstly, you cannot invest money in 1928. To be relevant to you, start looking at the graph when you first had money to invest. 1999? 2008?

Secondly, look at the Y-axis scale. This is NOT a LINEAR graph. This is a logarithmic scale. That little blip drop in Australian Shares value at the end is worth $331,375!!!!!  If you had $1,000,000 (Just retired, for instance) and put your money in shares in October 2007 that is how much money you would have LOST.

Here is a liner graph showing clearly (and more honestly) the drop in the All Ordinaries Index in the Australian Share Market during the GFC. The graph came from Sharewatch.

Mathspig Maths Mystery Box 1 graph 2


How much do we owe, um, let me see? Lots. Yes. Definitely,lots.

May 28, 2009

AT 8.50am on 26th Nov 2007 Mathspig stood outside the The Internal Revenue Service (called the Tax Office in Australia) on 44th St New York mesmerized by the National Debt Clock across the top of the building. It was a 13 digit-long digital clock in red  with the last numbers turning so fast Mathspig struggled to write them down. Nevertheless, this is what I wrote:

$ 9 075 182 859 960

Needless to say, all figures are in US dollars. Y0u can the National Debt Clock on youtube: #mce_temp_url#  moneyshot08-09-26

By October 2008 it was out of date. By then the National Debt was over $10 trillion or 14 digits. The clock was one digit short. But just to show that it is great to watch someone else’s National Debt ticking over you can view the current National Debt at : #mce_temp_url#   

When mathspig last looked at this National Debt Clock it was:

Adding $6,000,000 per minute and stood at:

$11 401 659 454 654

I will round this off to the nearest trillion: $11 000 000 000 000 Now you will see the cost of rounding off. I’ve just chucked out almost 500 thousand million dollars. That my rubbish bin could be so lucky. In maths we use powers of ten to write big numbers mainly because we are too lazy to write all those zeros:

11 trillion Correction



  Problemo 1 : Polish up your powers. You will find a free online powers of ten worksheet at: #mce_temp_url#

 Problemo 2: What are other ways of recording these big numbers? They can be written in long hand. How many millions, billions and trillions is the National Debt?Harry potter

Problemo 3: It is more fun I think to convert this debt into a workable unit. Harry Potter star, Daniel Radcliffe, 19, earnt $25 million to the year ending 30 June, 2008. What is the National Debt  in Harry Potters???????? 

Meanwhile, Harry Potter may be needed to solve the National Debt problem.




    Stop: The lesson to day is, however,  ‘People who collect taxes should be able to count’.