h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Change for a Dollar for Dummies: Higher Lower Mathematics - A87942883
Author: Dmitri Gheorgheni - Not Banned in China - U1590784

The Post Editor is innumerate, but can make change. However, I would deeply appreciate it if you'd all read this carefully to make sure I haven't got any sums wrong.

Written pursuant to a conversation I had with SashaQ about whether I could manage to write a guide entry with numbers in.

This entry will either prove or disprove the proposition.

kthxbai

I think this Entry can be helpful for many people. Couldn't find anything wrong with the calculations.

This Entry proves the proposition, thank you!

This Entry is very useful, even though (or rather because ) it has numbers in I enjoy that quote at the beginning - sounds like mathematical apocrypha to me as the ATM has more personality than one might expect, but that is funny!

Very interesting about the half-dollar being rare - in the UK the 50p often features commemorative designs because it is not as common as the 1p, 2p, 5p, 10p and 20p, but it is not as bulky as it used to be, and can be used in machines, so there are still a lot of them about.

I volunteer on a book stall occasionally so I 'make change' there, but it is easy these days as the books are currently all 50p so there isn't much choice of how to break a £5 note! Some people still think it's magic though Not to mention the staff at a little cafe I once frequented, who had to type the amounts into a calculator to add them up - they sometimes missed digits off and didn't realise the total amount didn't make any sense as they couldn't even work out an approximation in their heads... That was magic too, that I generously 'overpaid' almost every time!

The quarter is the coin that is the conundrum for me - reminds me of the quiz show Countdown A1106443 where, whenever the Numbers Game features 25 or 75, I struggle a lot more than if I've got the nice round numbers 50 or 100 to work with... Could you say a bit more in the instructions step 3 or 4? - the first example goes from nickel to quarter without involving dimes so that's magic! I can visualise the second example with 3 dimes very easily in relation to the coinage I'm used to

A couple of other queries:

I *think* I know what a "spindle" is, but I'm not sure I'm thinking what you're thinking...

What is a "penny loafer"?

As you know, there are 180 recognised currencies in the today and 19 different dollars (though I know how devastated you must be that the Mickey Mouse dollar is no longer available). There's the Australian Ozzy dollar, Bahamas dollar, Barbados dollar, Belize dollar, Brunei dollar, Canadian dollar, Cayman Islands dollar, Ecuador dollar, Fijian dollar, Guyana dollar, Hong Kong dollar, Jamaican dollar, New Zealand dollar, Singapore dollar, Solomon Islands dollar, Taiwan dollar, Trinidad & Tobago dollar, US dollar and Zimbabwe dollar.

Would you consider specifying in the title that it is the US dollar the entry is about?

<BB<

*gasp* A guide entry that isn't about the *UK*? How will we survive without safety labelling? Since I made it clear in the first paragraph I was talking about US currency - even the opening quote says 'Mathematical Association of America' on it in large, friendly letters - I thought I'd taken care of that.

But sure, I'll put it in the title to warn English people not to bother reading it.

Done.

Seriously, I don't really know how to make change in other systems these days since the advent of the Euro. And I'd promised to try an entry with practical maths in. If somebody wants to write a 'How to Make Change in...' for different currencies, that would be totally and help international travellers.

I'd never thought of counting in quarters being harder than counting by tens. See, weird measuring systems are good for the brain! I'll try tweaking that. (Also, rereading it, I realise that to Americans, the quarter solution is the preferred one, which is why we do that one first.)

And you've made the excellent point that my instructions were misleading!

I've fixed them now. I also put a little encouragement in the steps which, I hope, will get the reader to look back at the coins and play the guessing game. After all, this was supposed to be a maths game.

Explain 'spindle'. Okay... Will do! I note that you can buy them from Amazon UK:

http://www.amazon.co.uk/Fellowes-Spindle-Desk-Bk/dp/B001HA6QXC

Spindle gloss added.

Penny loafers are definitely a blast from the past. reference.com explains it succinctly:

'Why Do People Put Pennies in Penny Loafers? The penny loafer originated when a shoemaker named John Bass created a type of loafer called a "Weejun" that had a split strap across the top of the shoe. People added embellishments into the opening of this strap for decorative purposes, the most common being a penny.'

Both boys and girls used to wear loafers in the 50s and 60s. They were the Bass-style loafers with the slot for a penny. You'd find the shiniest ones you could to put in your new loafers, which you wore to school.

I had a pair of those things I wore for 10 years - from primary school through graduation. Of course, I'd had them reheeled and resoled. While in university, I decided they were kaputt, and tried to buy a new pair. The shoe clerk said disdainfully, 'Those are out of fashion. This is the Seventies.'



Thanks for checking the maths for me, Tav! I'm notorious for staring right at numbers and getting them wrong - ask Paulh. (I typed the wrong date on this week's Picture Quiz and had to redo it.)

Hey, some of us spent years of their lives working for banks doing International Currency Exchange. If you ever want to know about UK currency exchange regulations at the turn of the century, particularly with regards international cheques, and how long after you've paid in a cheque to your account before you can expect to see the money, let me know.
To this day I remember the mnemonic Good Zoo Keepers Never See Sad Zebras to help remember Ghana, Zambia, Kenya, Nigeria, Somalia, Sierra Leone and Zimbabwe.

<BB<

Now, you're talking. Good entry topic!

I think the only difference to doing this with Euros is that we don't have any quarter coins and 50 cents don't seem uncommon.

Thanks, Tav. I realised I've never done Euros. Just marks, drachmas,lei and such.

Ah, wait... we also have 2 cent coins and 20 cent coins.

Aha! Many more opportunities for making change!

This Entry is a useful guide indeed - I saw adverts recently for Monopoly A21141523 with a computer banker, so players don't have to handle actual cash! Removes one of the educational aspects of the game, I think...

Counting all the money and sorting the cards was just about the only interesting part of that game when we were small. No adult would play it, so we were pretty clueless.

We started playing games like that with the kids to teach them numbers.

Great idea, Tav. Learning that involves more than one sense - like sight and touch - is more effective than with one sense alone.

This is looking good Just a couple more points of clarification needed:

"Twentieth-century US coinage consists of six coins:" - I think you need to write the six coins in text here, in case people can't see the image.

Footnote 2 needs to be precise that it is the smallest number of coins possible.




"Learning that involves more than one sense - like sight and touch - is more effective than with one sense alone."

Yes indeed. That is a soapbox I get on to occasionally, when I read news of schools with lower than expected results in maths stopping everything else, eg geography or technology, just to do more writing in workbooks, which makes things worse rather than better for students who don't 'get' maths as an abstract concept... When I worked as an exam marker, one of my favourite maths exam questions involved students having to imagine turning a dial to set the temperature on an oven and then working out at what time the food would be ready Maths in action

I rewrote that sentence and the footnote. Good catch!

The multi-sensory approach also works with language, especially with learners (of all ages) who are more comfortable with spatial relationships than verbal ones.

"six coins: a penny (=one cent), a nickel (=five cents), a dime (=ten cents), and a quarter (=twenty-five cents)." - just need to add half-dollar (50 cents) and dollar (100 cents)

Thank you. (Multi-tasking does not always go smoothly. )