Posts Tagged ‘Math’

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Real World Maths: Surds and all that jazz …

October 12, 2022

Eddie Woo is an Aussie Maths teacher who runs his own Youtube Channel. So popular is this channel in October 2015, Woo won the NSW Premier’s Prize for Innovation in Science and Mathematics. This youtube clip won’t tell you where you will use surds, but it does something magical.

It compares surds to different kinds of music to help students understand why mathematicians go crazy over the concept of surds. This clip tells why maths is soooooo special. There is no guesswork or fake information in this maths. Maths must be accurate. And surds demonstrate this point. (Look for the 5 min mark)

Will you use surds in real life?

Maybe. Probably, not. But surds are used in mathematical programs that demand accuracy. eg. engineering skyscrapers, building satellite dishes, and even in video games. But you won’t see them. Like so much mathematics surds will be hidden in some algorithm.

Here are two Examples:

1. The Golden Ratio:

Often written a 1:1.61 the Golden Ratio or Fibonacci Sequence appears in art and nature and has an aesthetic appeal to the eye, but the accurate ratio is:

2. The Quadratic Function

Satellite dishes, headlights, torches, and bridges all designed using the parabolic arc. The parabola is defined by the quadratic function and sometimes solving for x produces an irrational no. namely a surd. Rounding off can introduce inaccuracies that can become more dramatic when scaled up to the sie of, say, a bridge. 

3. The Golden Ratio in Music

Mozart arranged his piano sonatas so that the number of bars in the development and recapitulation divided by the number of bars in the exposition would equal approximately 1.618, the Golden Ratio. Find more @ CLASSIC FM.

Back to Mozart.

In the above diagram, C is the sonata’s first movement as a whole, B is the development and recapitulation, and A is the exposition.

And here is Mozart’s Piano Sonata No. 1 in C Major as an example. Can you hear the Golden Ratio. Not really. But it’s there.

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Razzle-Dazzle them with Middle School Math that is, like, WOW!

September 4, 2022

 

10 Quick & Quirky Ways to Make the Math Classroom Rock!

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1. Tell a Story: Life, Death, and Geometry

This is middle school maths at its best. To understand Wild Fires you must understand the angle of a slope. REQUIREMENTS: Just this story and a white or blackboard to show how the fire speed changes with the slope angle. 

Background Story

On 5th August 1949 Wag Dodge was dropped by parachute with 14 other firefighters into Mann Gulch, a steep-sided gully in a Montana pine forest. Firefighters who parachute in to put out small blazes started by lightning are called Smoke Jumpers. As they worked their way down the sides of the gully the breeze was blowing away from them. But the wind soon shifted. This produced an updraft, which increases the speed of the fire front. The 15 Smoke Jumpers turned and started running for their lives uphill.

What you have to know

Heat rises and so there is a Chimney Effect pushing the fire uphill. The rule of thumb used by firefighters is:

Each 10º increase in slope, the fire front speed doubles. So a fire front traveling at 60 kph (37 mph) becomes a fire front traveling at 120kph (75 mph) moving up a slope of 10º.

What happened to the Smoke Jumpers?

When the fire front changed direction Wag Dodge and 14 other Smoke Jumpers found themselves running for their lives up a steep slope. What did Wag do next?

ANS: Here’s the amazing thing. Wag realised he could not outrun the fire at that point. So he stopped, took off his backpack, took out some MATCHES, and lit a fire in the grassy patch in front of him. Just before the firewall hit he threw himself face down on the burnt patch. He survived. The other 14 firefighters did not. You will find maths exercises here: METRIC UNITS and USA UNITS.

 

Requirements: SmartBoard to Project this link.

Try it first. You might be surprised.

 

3. Urban Myth Busted

Requirements: This story.

Goldfish Memory This is what Epidemiologists do. They find out if there are statistics to support the theory. These mathematicians have been providing vital information during the COVID-19 Pandemic.

According to the ABC news, this myth was busted by a 15-year-old Adelaide schoolboy named Rory Stokes. He fed his goldfish near a Red Lego brick. The fish started anticipating food near the brick. He took it away and replaced it several weeks later. The fish remembered the red brick!!! More here.

Other maths myths to check out:

Chewing food 32 times before swallowing helps you lose weight. Here.

You must drink 8 glasses of water a day. Here.

You are 6 degrees of separation from anyone in the world. Here.

It takes 43 muscles to frown and only 17 to smile. Here.

 

4. Beat this! Drum Rates in BPM.

Requirements: A pencil and a timer on a phone.

Can students manage a drumbeat to popular songs? Here are some songs with their BPMs (Beats per minute listed). 

Tones and I     Dance Monkey  98 BPM.

The Rubens  Live In Life  104 BPM.

Lady Gaga      Bad Romance     118  BPM

……………….Just Dance          119   BPM

Flume   Rushing Back   176  BPM   (Try the middle of the track. It varies)

Panic! At the Disco      186 BPM   (Recommended by Jog.FM for jogging)

More DRUM BEATS and a story about Drummers’ Brains here.

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5...MatHoudini

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Requirements: Phonebook.

Read the instructions at this link. Very simple. And you can amaze the students. Or Vice Versa. A student can amaze a maths teacher.

 

6.  Can you make a Square Bubble?

Requirements: pipe cleaners or stick cube and detergent and a bucket with water.

All ages love this exercise.

How? Read the link here.

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7. Photo Scavenger Hunt

Challenge: Students use a smartphone to take 5 mathsy photos for homework. Ideas here.

However, start in the maths room. Look for parallel lines, angles, rectangles, spheres, parabolas (not in the textbooks). See parabola below.

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8. Barcode Maths

Requirements: A product with a barcode.

Read this link and check the barcode.

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9. Secret Code

Requirements: Box of matches, an accomplice.

Read this link and amaze the class.

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10. Rolling coin Paradox & the Radius 

Requirements: 2 large coins. 20c in Australia, Half-$ USA or 25p UK.

Read this link first. It’s so counterintuitive.

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No Frills MATHs Skills for Parents 4: FRACTIONS for Beginners

June 6, 2022

Here is a post on Lego Fractions by New York Grade 3 teacher Alycia Zimmerman. Surprisingly I found this on an art website.

teaching-children-math-lego-blocks-alycia-zimmerman-thumb640

teaching-children-math-lego-blocks-alycia-zimmerman-8

Just play with the Lego blocks. Add and subtract … you can even multiply and divide.

Next time.

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No Frills MATHs SKILLS for Parents 3: Pre-Algebra

May 23, 2022

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No Frills MATHs SKILLS for Parents 2 : Algebra

May 4, 2022

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No Frills MATHs SKILLS for Parents 1: Super Easy Long Mult and Division

April 27, 2022

Go to BASIC MATHEMATICS here. It will take you through basic maths by your Grade level.

NB. If you can’t remember how to ‘borrow the 1’ for division or ‘carry the 2’ for multiplication here go back to the link above.

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Mona Chalabi’s Data Art: Maths never looked so good even the dick graphs

April 10, 2022

Mona Chalabi is a British-Iraqi data journalist and illustrator based in London. She specialises in all things data.

An outstanding communicator her work proves that MATH can be artistic and ART can be data-based. She is an honorary fellow of the British Science Association.

Mona Chalabi Self Portrait on INSTAGRAM

WARNING: Mona Chalabi INSTAGRAM account is politically graphic and contains sexually explicit graphs. Yeah! Dick graphs etc. The Instagram links in this post connect with individual illustrations.

1. Mona Chalabi on Jeff Bezos’ Wealth. 

I found Mona Chalabi through her illustrated New York Times article (7 April, 2022) 9 WAYS TO IMAGINE JEFF BEZOS’ WEALTH. 

So Jeff Bezos personal wealth is $172 Billion (US$) Her Toblerone Block vs Mt Everest comparison was in this article.

NOTE: Median wealth is the mid-point wealth ie. 50% of Americans have more wealth. 50% of Americans have less wealth.

2. Mona Chalabi CAFFEINE DATA ON INSTAGRAM

Mona also includes relevant the data in her posts. eg.

 

3.  Mona Chalabi on OUR MOST COMMON FEARS on INSTAGRAM

4. Mona Chalabi on Earth’s Orbit on INSTAGRAM

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Dave Grohl and The Curious Nature of Drummers’ Brains

March 4, 2022

Live music is back.

The Foo Fighters play a stadium concert in Geelong TONIGHT. This is the first stadium concert in Australia in 2 years!!!!! Dave Grohl, the FF’s guitarist,  is a legend. He played drums for Nirvana and is considered by many to be the best drummer in the world. Meanwhile, Taylor Hawkins, the drummer for the Foo Fighters, is also considered one of the best rock drummers ever. 

In honour of this auspicious occasion and to work out what might be going on inside these rock legends’ heads, I’m reposting (below) the math article about drummers’ brains.

 

 

In a 2011 article in the New Yorker Burkhard Bilger wrote about neuroscientist David Eagleman and his research into time and the brain especially drummers’ brains.

Eagleman New Yorker

Some of the drummers he has interviewed and/or tested include William Champion of Cold Play, Brian Eno of Roxy Music and Larry Mullen, Jnr of U2.Roxy Music with Brian Eno

Eno, on keyboards (above) who was working on a U2 album,  talks about Mullen’s amazing timing.  They were using a click-track (computer generated beat) when mMullen complained he couldn’t drum to it. ENO adjusted the beat. Mullen was happy.

larry Mullen

ENO adjusted the beat by 6 milliseconds!!!!!!!!!

6 thousandths of a second or 0.006sec.

Cool Larry Mullen Jnr Drum solo

Tempo is measured in beats per minute or bpm. 

Drum Beats for different tracks:

Drum Beats

Here are some drum beats provided by Justin Alan Cox so you can get your timing right:

60 bpm

80 bpm

100 bpm

120 bpm

Drummer Maths:

How Cool a Drummer are you?

Pick a beat and see how accurate you can beat tempo. Time how long it takes you to beat out 60, 80, 100 or 120 drum beats using a pencil.  It should, obviously, take one minute if you are an ENO or a Mullens.

What was the difference in time in seconds?

But drummers like Eno, Grohl and Hawkins have other problems!!!!!

Bilger’s conclusion:

‘Like perfect pitch, which dooms the possessor to hear every false note and flat car horn, perfect timing may just makes a drummer more sensitive to the world’s arrhythmias and repeated patterns, Eagleman said—to the flicker of computer screens and fluorescent lights. Reality, stripped of an extra beat in which the brain orchestrates its signals, isn’t necessarily a livelier place. It’s just filled with badly dubbed television shows.’

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What’s the Maths Curriculum got to do with it? WHEN Maths is, like, soooo BORING!!!!!

February 22, 2022

Australia is reviewing its Maths Curriculum.

Sides are taken. Arguments are rife. See the excellent article by Donna LuCracking the formula: how should Australia be teaching maths under the national curriculum?, The Guardian,13 FEB, 2022)

Should teachers teach? Or students explore problems? (Called Cognitive Activation in academe!)

Why not, both? Then add outdoor maths (below) plus defronting the classroom sometimes and try some maths selfies for homework. More ideas here

It doesn’t matter what’s written in the curriculum, the biggest problem in maths for students is

BOREDOM.

Here, to tackle boredom are:

41 Maths things to do before you’re 12


Mathspig outdoor play quote

mathspig outdoor-play-app

A growing body of research shows us that outdoor play leads to better physical and mental health, has positive effects on cognitive function and learning, and reduces the incidence of behavioural problems.” Maria Zotti, Nature Play, SA.

Peter Dunstan, Principal Kilkenny PS, SA, writes in SAPPA magazine, Primary Focus, that outdoor play fosters “wonderment, independence and freedom” as well as “social skills, imagination, creativity and problem solving”.

Inspired by SAPPA and NaturePlay,  Mathspig has produced her own outdoorsy maths list:

 Mathspig 41 maths things 1Mathspig 41 maths things 2mathspig 41 maths things 3

Mathspig 41 maths things 4mathspig 41 maths things 5

References:

7. Robin Hood Give us your best shot.

9. You can measure the volume of your lungs by blowing one breath into a balloon and pushing it into a full bucket of water. Measure the overflow.

15: Outdoor Maths: Times Tables

21. Light intensity links. Here and here.

25.  Sound Volume Measurement

36. Killer heels that really kill.

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NATHAN CHEN wins Gold but Figure Skating Scores can be BAD MATH

February 10, 2022

Nathan Chen, 22, USA, wins GOLD in the Men’s Figure skating with 5 brilliant, soaring quadruple jumps executed to perfection to Elton John’s “Goodbye Yellow Brick Road” and “Rocket Man.”

Nathan Chen’s Winning Performance on You tube HERE.

According to the fab NBC video, Mathletes,  nine Figure Skating judges score competitors for the complexity of each element (eg. Triple axel or triple spin jump) and the quality of the performance producing a score out of ten.

Tessa Virtue and Scott Moir(Above) GOLD Medal performance at Pyeongchang 2018 here.

Kailani Craine, Australia

figure skating score 9 judges nbclearn

This is a typical figure skating score card for one competitor.

The final score, however, is based  on the average for only 5 of these scores. Two are eliminated by random selection (Red Brackets). Then the top and bottom scores are removed and the remaining five scores averaged.

Screen grab NBC Mathletes

Screen grab NBC Mathletes

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Now consider the IDENTICAL SCORE CARDS

of Skater A & B:

figure skating score A

Skater A:

Four scores are removed. Two by the random selector (in brackets) and then the top and bottom scores (with line drawn through them)

7.00 + 7.00 + 7.00 + 6.75 + 7.00

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=  34.75/ 5 = 6.95

figure skating score B

Skater B:

Four scores are removed. Two by the random selector (in brackets) and then the top and bottom scores (with line drawn through them). But this time the random selector eliminates two low scores.

The average:

7.00 + 7.25 + 7.00 + 7.00 + 7.00

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=  35.25/ 5 = 7.05

Same score cards but Skater B gets a higher average score than Skater A.

Skater A is, in fact, beaten by a random number selector!!!!