The rather strange racetrack owner and the MASSIVE lorry

Image by AndreasIken from Pixabay

For week 25 (of the countUP) here is a neat bit of horsey maths from one of my favourite YouTubers.

I can’t think of a reason why you would need to work out which are the three fastest out of 25 horses, but maybe you can. And anyway, let’s suppose that’s the case.

OK, you have your 25 horses and you take them to a racetrack. Hey, that’s a MASSIVE lorry you have. Does it need a special licence to drive it?

The racetrack owner says, ‘Please use my racetrack but only 5 horses at a time please. Oh and I need it back, so be as quick as you can.’

Right then! 25 horses to be raced 5 at a time. What’s the smallest number of races it will take? Go!

We're starting something different this week

Exciting news: the adventures of Megan, Amy, Jack and all the people mentioned in the professor's video HERE are getting close to a first full draft of a book, but this means things are getting busy and there isn't always time to remember which week of the count up we've reached (but I'll try) so for this final stretch towards the finish line, let's do something different.

Is anyone out there heading towards their GCSE Maths and feeling worried that they might not do very well? Here are some top tips for top marks:

If your first thought is evasion

At the sight of an equation

And you'd like to up your mark

But you're totally in the dark

Then try this neat persuasion

From a YouTuber named Clarke

In the video, Jake mentions Corbettmaths. Find them HERE.

And by the way, it's week 18 this week, but who's counting?

Week 17 of the count up

17

17 is a prime number like 13. Its connection with the number 13 and with cicadas is that cicadas can incubate underground for years, but not a random number of years; either 13 or 17.

Why is this a countUP and not acountDOWN?

Week 16 of the count up

16

Week 16 of the count up and here’s a maths problem given as homework to 9 year olds in Taiwan. Never mind “Mind Your Decisions”, which is where this comes from, this one will blow your mind.

Why is this a countUP and not acountDOWN? 

Week 15 of the count up

15

Week 15 of the count up and here’s another puzzle from Mind Your Decisions. And since this is week 15, here’s a hint. The answer is NOT 15.

 

Why is this a countUP and not acountDOWN?

Week 14 of the count up

14

Week 14 of the count up and here’s something different from a YouTube mathematician called Presh Talwalker whose YouTube channel is called Mind Your Decisions. In this video he shows you a neat way to work out the radius of a heart.

Why is this a countUP and not acountDOWN?

Week 13 of the count up

13

13 is a prime number and has an underground connection to cicadas – check out week 17 for more.

 

Why is this a countUP and not acountDOWN?

Week 12 of the count up

12

Remember the sum back in week 2? The answer is ‘twelve plus one’.

 

Why is this a countUP and not acountDOWN?

Week 11 of the count up

11

Week 11 of the count up, and time to take stock. 

All the new cast is now embedded in the book, that includes Solo, Fmelodie, Tristan and Starlight Piglet, but Megan and Amy haven't properly met them all. At least not - as Amy would say - been introduced in a 'pleased to meet you' kind of way. In fact, Megan isn't quite sure she wants to meet Tristan properly. She has a feeling they've already met and that she didn't do well out of the encounter.

I’m not planning to get to week 1000, but I have a neat 1000 fact so I’ll put it here. It’s about the letter ‘a’. Although not as common as ‘e’, it is the second commonest vowel in the English language. Yet how many times would it appear if you were to write out the numbers from 0 to 1000?

Answer (surprisingly): just once. 

It is still a countUP but before too long it'll be a countDOWN,

Why is this a countUP and not acountDOWN.

Week 10 of the count up

10

We’re now in week 10 of the count up. Do you remember that back in week 6 I said that there was a connection to the number 10? It is that 10 factorial (usually written 10! And meaning 10*9*8*7*6*5*4*3*2*1) equals the exact number of seconds in 6 weeks.

 

Why is this a countUP and not acountDOWN.

Week 9 of the count up

 9

Nine is an interesting number to multiply. If you add together the digits of the answer, you always end up back with 9.

2 * 9 = 18

Add together 1 and 8 et voila! 9

Or really go mad and try something bigger:

56 * 9 = 504

5+0+4 = 9

And even where you don’t immediately get back to 9, then add together the numbers of the answer until you get back to a single digit and it will always be 9.

55 * 9 = 495

4+9+5 = 18

1+8 = 9.

 

For an explanation of why this is a countUP and not a countDOWN, CLICKHERE for the New Year post

Week 8 of the count up

8

This week I’m using the fact that 4 + 4 = 8.

Pick any 4-digit number (it must contain at least 2 different digits, so it could be 4985, or 5583 etc but not 5555)

1.     Write the digits in ascending order e.g. 4985 would become 4589

2.     Now write the digits in descending order e.g. 4985 would become 9854

3.     Now subtract the smaller number from the larger e.g. 9854 minus 4589 equals 5265

Now start again at 1 with this new number, and eventually you will end up with 6174, no matter where you start. The number 6174 is known as Kaprekar’s constant. 

 

For an explanation of why this is a countUP and not a countDOWN, CLICKHERE for the New Year post

Week 7 of the count up

7

Seven is a number that crops up all over the place: 7 dwarves, 7 days in the week, 7 wonders of the world etc. It is also popular as a ‘favourite number’ and has come top in favourite number polls.

For an explanation of why this is a countUP and not a countDOWN, CLICKHERE for the New Year post

Interrupting the count up with an audio announcement

Horse of a Different Colour is due out as an audiobook any day now. Watch this space! But as for Horse of the Same Colour, this is week 6 of the count up and things are going well.

6

The number 6, because it denotes 6 weeks, has an interesting connection to the number 10 – check out week 10 for more. If I was counting up in days, this connection wouldn’t work.

 

For an explanation of why this is a countUP and not a countDOWN, CLICKHERE for the New Year post

 

Week 5 of the count up

 5

Five is an odd number and like all odd numbers, it has at least one ‘e’ in its name.

For an explanation of why this is a countUP and not a countDOWN, CLICKHERE for the New Year post

 

Week 4 of the count up

 

4

The number 4 has 4 letters in its name: f-o-u-r. Bet you can’t find any other number that does that.

For an explanation of why this is a countUP and not a countDOWN, CLICKHERE for the New Year post

Week 2 of the count up

2

‘eleven plus two’ is an anagram of another sum that also equals 13. Can you work out that sum? The answer will be in a few posts from now.

For an explanation of why this is a countUP and not a countDOWN, CLICK HERE for the New Year post

A unique number

A happy, safe and prosperous 2021 to everyone

Having introduced all the new characters and hinted at the BIG SECRET, I had hoped to start a Countdown to Publication. But I can’t because I don’t have a publication date yet.

However, the book will be published in 2021 so instead of a countDOWN, I’m doing a countUP. When I get a date, I will reverse direction and count down.

This is week 1.

1 is an interesting number. It’s neither a prime number nor a composite number. Every other whole number is one or the other.