## 41 Maths things to do before you’re 12

February 8, 2023

Summer Holidays are done. School is BACK in Australia. But how do middle school teachers get students excited about Maths? Here are some ideas.

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:

References:

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.

21. Light intensity links. Here and here.

## Dangerous Math: Death by Snake, Spider, Quad bike, Kangaroo, Raccoon and Vomit

November 17, 2022

It’s almost summer in Australia. In Melbourne we’ve had floods, mosquito – mozzie- numbers surge and, last Wednesday, I nearly stood on a Tiger Snake that was escaping the floods near the Yarra River!

This post, however, 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 soundtrack from JAWS to feel the fear. Then we see news footage like the attack below and think it happens all the time. Look at that fin. It’s enormous! But sharks are not THAT dangerous. We really need to look at the statistics to understand the level of threat. See below.

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.

# THE MATHS:

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 2022

……..Aust…26 million = 26 x 106

……..USA…332 million = 332 x 106

……..Canada…38 million = 38 x 106

……..UK…67 million = 67 x 106

But we’re doing this for the SHARKS!!!

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

1. 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

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

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

## 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:

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.

## Outdoor Maths Adventures: Middle School

September 16, 2022

As the weather improves – Spring in Melbourne, my city & Fall in USA & Autumn in the UK – it is an ideal time to take math outdoors. Here are some fab exercises for Middle School Math.

Lego Man soccer fields will vary in size depending on the height of each player picked by each student. This does your head in. It is really challenging maths!

Don’t forget to throw in Mathspig’s lame protractor jokes.

You’ll find full calculations at the Maths is Fun blog.

You’ll find more fab outdoor junior and middle school maths activities at the terrific Maths and Movement blog.

Some students will discover their co-ordinate point is not on the grid. Students should then work out that they will need a different scale for the y-axis. You can get more inspiration at the Stand Again blog.

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

September 4, 2022

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

…………………………………………………………..

## 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.

……………….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.

## ………………………….

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.

# 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.

# 8. Barcode Maths

Requirements: A product with a barcode.

# 9. Secret Code

Requirements: Box of matches, an accomplice.

## ………………………………………

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

## When Area Calcs mean Big Bucks

August 25, 2022

Bank Notes returned to RBA data.

RBA grids for damaged notes.

## Crazy Guy uses Infrared Sensors on Xbox Kinect to create WoW! Synth-Pop VIDEO

August 7, 2022

The aim of this post is to show middle school math students that MAPPING is used in the REAL WORLD of Synth-Pop Music Video Production.

## Amazing and Terrifying Wildfire Maths . . . . . . . . . . . . . . METRIC UNITS

July 25, 2022

With wildfires  burning across the US and Europe , Mathspig had to update this firefighter maths post for middle school classrooms.

Radiant Heat Stats WA Fire Dept FACEBOOK, Australian Bushfires 14 NOV 2019 MyFireWatch WA

Wildfires USA 2022 Map: NASA

# Background Story

On 5th August 1949 Wag Dodge was dropped by parachute with 14 other fire fighters into Mann Gulch, a steep-sided gully in a Montana pine forest. Fire fighters who parachute in to put out small blazes started by lightening 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.

# METRIC UNITS

## Time Trial:

Mark out a 10 m course. Make 3 time trials.

t1 =

t2 =

t3=

tav = (t1 + t2 + t3)/ 3 =

Your Speed S = 10/tav = ……… m/sec

## HOW FAST IS A GRASS FIRE?

This will, of course, vary depending on the wind speed. A typical grass fire in Australia in a flat area can travel at 20kph (up to 30 kph) in a gentle breeze.

Fire Front Speed Grass Fire

Fire Front Speed = 20 kph = 20 x1000/(60 x 60)

= 20 x 0.27777777 = 20 x 0.28 m/sec

= 5.6 m/sec

# CAN YOU OUT RUN A FIRE?

Average Running Speed Boy 13–14 yo = 3.0 m/sec

Average Running Speed Girl 13–14 yo = 2.4 m/sec

We’ll assume, boy or girl, that you are really motivated and can run away from the fire at top speed of 3.0 m/sec. Now calculate the distance you can run and the fire front moves in 10 secs intervals up to 1 minute.

This is not looking good. See more Firefighters Need Maths here.

We can do very accurate calculations using simultaneous equations. Wildfire Algebra: Detailed Worksheet using simultaneous equations and solutions  here.

## NOW YOU ARE RUNNING UP HILL. WHAT HAPPENS?

We’ll assume, due to being motivated by having a fire licking your heels, that you can run at your top speed up hill for a short time, at least. But here is the problem.

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

Each 10º increase in slope, the fire front speed doubles.

Now you can calculate the distance travelled by the fire front up a slope at a 30º angle.

Don’t forget you can use the WEB 2.0 Calculator here.

Even at your top running speed, which is unlikely up a slope, you can run 180 m in 1 minute. In that time the forefront has moved 2688 m or 2.7 km.

It depends how far away you are from the fire front, but it seems you cannot out run this fire front.

Again we can do very accurate calculations using simultaneous equations.

See Firefighters Need Maths here.

Wildfire Algebra: Worksheet and solutions here.

# CAN YOU OUT RUN A WILD FIRE?

High winds can turn a bush or forrest fire into a WILD FIRE with wind speeds up to 110 kph and temperatures up to 2000 °C, which can and does melt glass and cars.

The fire front speed doubles with every 10º, so speeds for the fire front can reach 220 kph, 330kph and up to 550kph.

# 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 out run the fire at that point. So he stopped. Took off his back pack. 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.

June 19, 2022

## 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.

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

Next time.