Archive for the ‘Ratio’ Category


Dangerous Maths 2: Death by Snake, Spider, Quad bike, Kangaroo, Raccoon and Vomit

August 7, 2015

This post is really a PR exercise for sharks. We fear them. We’re horrified by the thought of being eaten alive!!!. We only have to hear the sound track from JAWS to feel the fear.

Why do we fear sharks? Look at the numbers. REALLY. Show your students. What about stairs??? Quad bikes? Chairs? Bees? That’s when you should feel the fear!!! We are irrational beings. This is why we need maths. We can make rational decisions using maths. There is also a safety message here. The maths speaks for itself. We won’t hammer it.


There is lots of maths you can do with these tables.

  • Bar Graphs
  • Pie Charts
  • Ratios (What’s the ratio of death by Snake to Quad Bike?)
  • Fractions (Show death by jet ski to falling down stairs as a fraction)
  • Percentages
  • Powers to the base 10. How many deaths occur in each country per 100,000 or 1 x 10head of population for, say, Quad bikes or ATVs? We can use these numbers to compare death rates and find out how dangerous riding a Quad bike is in each country.

……..Population Data

……..Aust…23 million = 23 x 106

……..USA…319 million = 319 x 106

……..Canada…35 million = 35 x 106

……..UK…64 million = 64 x 106

But we’re doing this for the SHARKS!!! Death Australia Mathspig

  1. Cyclists. 2. emergency lanes 3. fell off a chair 4.QUAD BIKES. 5. Horse, donkey. 6. buses 7. Cow, bull. 8. ice skates, skis or skateboards. 9. Venemous snake 10. kangaroo 11. bee 12. emu 13. Jet ski 14. Shark 15. Crocodile

Death USA Mathspig 21. Quad Bike or ATV: In 2007, 107 children younger than 16 were killed on ATVs. 2. Cyclists 3. choke on vomit  4. Cats, cows, horses, pigs, raccoons. 5. Bees, wasps  6.PWC or Jet Ski 7. Lightning 8. Xmas tree fires 9. Snowboard 10. Venomous Spider  11. Scorpions 12. Venomous Snakes , lizards. 13.Crocs & gators  14. Shark Death Canada Mathspig

  1. ATV Quad Bike 2. Canoe  3. Kayak 4. PWC or Jet Ski  5. Unpowered inflatable 6. Avalanches or landslides. 7. Lightning 8. Toboggan 9. Moose –Car collision 10. Bears (All Nth America) 11. Rattle Snake 12. Wolves 13. Shark

Death UK Mathspig

  1. falling down stairs.  2. Cyclists.  3. Choke on vomit   4. Falling off Chairs 5.  QUAD BIKE or ATV 6. Buses 7. Struck by cow, horse, other mammal 8. hornets, wasps, bees. 9. PWC or jet ski .10. Parachutists. 11. Skateboards, ice skates, skis 12. Canoe. 13. Shark 

The Rosetta Project scaled down to a Lego Universe

November 28, 2014

According to Warwick Holmes, ESA:

The images were taken by the OSIRIS-Narrow-Angle-Camera on-board Rosetta spacecraft orbiting 15.5km above the surface of Comet-67P. They show the Philae trajectory before and after the first touchdown, which occurred at 15:34 GMT (12 Nov).  As previously reported the harpoons did not fire into the comet to hold Philae down.

The small inserted images show the imprint of the three Philae foot-pads left in the dusty surface of the comet (compare “before” 15:23 image and the “after” images at 15:43)  Philae first touchdown was at 15:34 GMT.

1 OSIRIS_spots_Philae_drifting_across_the_comet  2
Philae bounced off the comet surface after the first touchdown and remained “airborne” for 1hr 50min.  The first bounce was 1km high and went 1km directly east on this image.

Philae then touched down a second time resulting in a much smaller second bounce which lasted only 7 minutes.  The gravitational force on the surface of Comet-67P is 1/50,000th of (“g”) Earth’s gravity, hence the very high and long re-bounds.

This image does not show the second or final third touchdown positions as they were outside the field of view of this image as Philae continued heading east with respect to this image.
1a Rosetta lander on comet

Finally, Philae completed 100% of the science data acquisition sequence that was planned on the surface despite the “rough” landing(s).  It will probably be several months before exact scientific findings are being published as the scientists shall be spending many weeks processing and examining the plethora of scientific data from Philae and Rosetta over the landing site.

 This is fabulous. Live Comet up date here

To appreciate the distances involved we will scale everything down to the

Lego Universe:

2 Lego Space Cadet Human Ratio Mathspig

3 Lego Scale philae and comet

4 Lego Universe 1 mathspig

5 Lego Universe 2  Mathspig More Rosetta data from Warwick Holmes, ESA.

6 Rosetta Data


The Rosetta Project … like throwing a dart from Sydney to Perth and hitting the bullseye

November 28, 2014

Many commentators in Australia claimed that the Philae landing was:

This is equivalent to hitting the bullseye of a dartboard in Perth from Sydney. With a billion euro ($1.4bn) dart. While blindfolded (as the mission was powered down for almost the entire journey). ABC The Drum

Did they get the maths right?

Inner bullseye of dartboard = 12.7 mm

1 Dartboard

67P comet = 4.1 km = 4,100 m at widest point

Distance comet from earth = 520 million km

 Actually, hitting the 67P comment was more like roulette as the Rosetta mothership swung into orbit. And, as the earth and the comet are moving, the distance constantly changes, but you can watch the distance changing here.

Fabulous Graphics from the Daily Telegraph

Fabulous Graphics from the Daily Telegraph

In the Dart Throwers Universe

We will assume someone can stand on earth and throw a dart at the comet … Yes! They would need very big triceps.

3  Dart throwers universe correction


So the commentators aren’t even close. It would still be a feat hitting a bullseye with a dart from 160km, but that would be from Sydney to, um, Nowra on the coast. 


Comet vs bullseye ratio mathspig

Mt Everest RAtio

4 Dart Throwers universe 3

The distance from Sydney to Perth is 4100 km. At best the commentators would be talking about throwing a dart from Brisbane to Adelaide is 2044km (below).

Brisbane to Adealide


3. How far can a bio-fuel Mini drive on 1 kg of human fat?

September 30, 2014

man vs mini 5b

Of course, in heavy traffic you are burning up the bio-fuel/fat getting nowhere.

Fuel Consumption (F) can plummet, even for the Mini, from 3.4 kg/ 100 km to 6.8 kg/100 km to 8.8 kg/100km. You may as well get out of the car and walk!!


In Biodiesel

Consumed walking

In FAT including Human Fat


Outdoor Maths Adventures: Grade 3 – 5

June 30, 2014

Outdoor Maths 1 Mathspig 2

This fab idea comes from Juliet Robertson, an outdoor education consultant in Scotland. Her blog Creative star learning is one of the most inspiring outdoor maths blogs you will find.

Outdoor Maths 2 Mathspig

Outdoor Maths 3 mathspig

Outdoor Maths 4 Mathspig

Outdoor Maths 5 Mathspig

Outdoor Maths 6 Mathspig

Outdoor Maths 7 Mathspig

Outdoor Maths 8  Mathspig

Check out Mathpig’s protractor joke here.

Outdoor Maths 9 Mathspig

Outdoor Maths 10 Mathspig

Another fab idea from Juliet Robertson.



2. Make a 3D Mini Me

October 24, 2013

The UK supermarket chain, Asda, is currently trailing 3D in-store printing of mini-me figurines. Cost: £ 40  (€ 47 or $Aus 67 or $USA 64)

Customers can buy 3D coloured versions of any person or object including the family car or dog (if Trixy can keep still for 2 mins) scaled down to an 8-inch figure.

Picture 2

Now you too can play games with yourself. (Warning: Avoid wording involving ‘play with’ and ‘yourself’.)

It takes two minutes using a hand-held scanner to create the 3D image and 6 – 8 hours for the 3D printer to produce the figure.



The Virtual You

3D body scanning already exists so you can create a 1:1 scale avatar (A Mevatar, perhaps?) of youself for online shopping. By combining this technology with 3D printing the scaled-down Mini Me concept was born.

YOu can walk your personal exact-scale Avatar into an online shop and try on clothes!

YOu can walk your personal exact-scale Avatar into an online shop and try on clothes!


Maths is involved at every stage of the Mini Me production to produce the scanner, the scanner program, the printer and the printer program.

It is the scale that is intriguing.

The scale used by the 3D printer is approx 1:10 ratio.


According to the BBC average man in England is 5ft 9in (175.3cm) tall and weighed 13.16 stone (83.6kg) and woman is 11 stone (70.2kg) and  5ft 3in tall (161.6cm).

3D printers use materials from brass to silver to ceramics so figurines can be quite heavy.  Assuming the ceramic material has a similar density to the human body, the 1:10 scale male figurine would weight over 1 stone (8 kg) and a female 1 stone plus (7 kg)!

Will shoppers be staggering home in York carrying 7kg figurines?????


Wait a minute:

mini mathspig Me

1:10 scale along each axis produces an overall scale of 1:1,000
1:10 scale along each axis produces an overall scale of 1:1,000

10 by 10 cube

Mini Me Mathspig is just 1/1,000 of Big Mathspig

or one little cube in the pack of 1,000.


The supermarket figurine @ 1:1,000 scale by volume (and, assuming, weight too) would weight 83 gm ( 3 ounces) for men and 70 gm (2.5 ounces)  for women. That’s more like it. The figurines will be, in fact, a little heavier as customers will be scanned wearing clothes and shoes, we hope, or the scanning sessions at the supermarket will be really weird.


What next?

How about your face on a Star Trek Figurine?

Done. See Engadget.

Yes, mathpiggies, we want maths to boldly go where no maths has gone before ……

Star Trek pic


5 Wrangle an Orderly Tangle

April 9, 2013

Maths-is-Awesome Activity

Wrangle an Orderly Tangle

Skill: Geometry, scale, ratio, measurement

Level: Junior & Middle School

100.1 Justin Meyer math-craft-monday-community-submissions-plus-make-orderly-tangle-triangles.w654

100.2 math-craft-monday-community-submissions-plus-make-orderly-tangle-triangles.w654

There are some wonderful projects at Mathscraft. But one students of any age will enjoy is creating an orderly tangle of triangles below. You can find a PDF template download for thise triangles @ the Mathscraft link above.

100.3 math-craft-monday-community-submissions-plus-make-orderly-tangle-triangles.w654

And this Orderly Tangle of 4 Triangles can be made on any scale from cute earrings to ORDERLY MONSTER TANGLE. Go wild mathspiggies.