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Loitering at NCTM

This was on an older, now deleted, blog of mine.  Causing Trouble at TI Workshop reminded me about it.  Someone might enjoy it…

Loitering at NCTM

Last week I spent my spring break loitering at the math teachers conference in Anaheim.  I learned so much it’s been hard to contain it all.  Here are some of my observations:.

I learned that no-one checks your badge to see if it’s counterfeit.

If you stay at the hotels, the daily parking is $16 where if you only drive in for the day it is $8.  And if you park in Garden Grove and walk, it’s free.  I would think the nightly hotel bill of $160 would offset some of the parking expenses.

I was pleasantly surprised when the parking attendant remembered me from my visit two days earlier.

If you buy a hot dog and soda at the Anaheim Convention center it costs $9.50.  I would think the $180 registration fee would offset some of the hot dog expenses.

I learned that $180 is actually inexpensive for a conference of this size and that the many vendors probably made up the difference.

You can get a lot of free stuff from vendors who want you to spend your school’s money on a lot of expensive stuff.

There are schools that can’t afford the expensive stuff so their teachers spend their own money on less effective substitutes.

I learned that far too many teachers spend their own money on less effective substitutes.

A cheerleading competition was scheduled next door.  (I assume it was to cheer on the math teachers.)

People came as far as Australia.  (To the math convention.  I don’t know about the cheerleading one.)

I met a principal that wants me to move to New Mexico.  (I assume it was to teach there.)

I met a teacher from Compton, California that doesn’t think merit pay based on student performance is fair when she has Algebra classes with 40 plus at-risk students while other districts have more motivated classes of thirty students or less.

She told me that she is considering quitting.

I met a surprisingly large number of people who were looking for the boat show.  (They must have walked in from Garden Grove and didn’t see the directions.)

I discovered there is free wireless available on the second floor of the Anaheim Convention Center but not anywhere else.

I did learn some math teacher stuff but won’t bore you with the details…

Cost to attend London Olympics

I’m tired of annoying commercials.  An unnamed credit card company has been running an ad implying you could see the London Olympics using their “Rewards Program.”  I decided to see what you would have to spend to get your “free” trip to London.

I Googled the following expenses and took the cheapest quote from the first page of results.  (I’m sure they are teaser rates to get you to visit the site.  The only way to get to London from LA for $585 is probably by hitchhiking and swimming.  But they illustrate my point.)

Flight to London  $585×2 = $1170

3 Nights at a Hotel  $29×3 = $87  (A little hard to believe…)

The most popular events:

  • Archery Finals £30
  • Fencing Finals £30
  • Table Tennis Finals £45

Total for events 105×2 = £210 or ~$327

Total cost = $1584

(The highest price tickets I saw were £450 for diving, swimming and gymnastics…)

A friend recently exchanged 14,500 “Reward Points” to credit her account $100.  If I use the ratio to figure out how many Reward Points I need to go to London…

1584*(14,500/100) = 229,680

For most of their cards you earn 1 point for every $1 you spend on purchases.

Soooo…  You have to spend almost 230 thousand dollars to get your free trip to the London Olympics!

But wait!  There are other ways to add points.  You can link an eligible checking account and earn 50 points (I think) a month.  So you only have to do this for 229680/50 = 4594 months or 383 years.  (I rounded to the nearest year.)

But wait!  If you’re a few points short, you can buy 1000 points for $25.  So your free trip to London only costs 229,680*(25/1000) = $57,420.  (Much less expensive!)

Or you can do some combination of these things.

The least expensive way to see the Olympics is NOT using their credit card reward program.  I’ll be watching them on my TV.

Update:  I forgot you have to eat!  Take some granola bars….

Image from The Warshaw Curve

Top Paid Games (in the previous x days!)

I was browsing the Top Charts in the Apple App Store and was thinking about the three categories: Top Paid Games, Top Free Games and Top Grossing Games.  I’m assuming Top Free Games is simply ranked by the number of downloads.  An app with more “sales” gets a higher ranking.  So what is the difference between Top Paid and Top Grossing Games?

I’m guessing Top Paid Games is also based on the number of downloads.  And Top Grossing Games is, obviously, based on the total income.  Wouldn’t they be the same list since more sales equals more money?  Only if they were the same price…

I am now going to make up some variables!  Let’s say the number of downloads is N for any game and the price is P.

Top Paid Games is simply based on N.  AirAttack has the most downloads.  So it is, right now, ranked number 1.  The Top Grossing Games is based on total income which would be N*P.  So a game with fewer downloads could move up the list by having a higher price.  That’s what happened with Civilization.  It’s price is $39.99 (a ripoff in my humble opinion!) compared with the price of $0.99 for AirAttack.  AirAttack would have to have over 40 times the number of downloads to beat Civilization on the Top Grossing Apps list.

I could even get crazy and estimate the relative popularity of games by using the formulas (where the subscripts refer to consecutive games on the Top Grossing list):

N1P1 > N2P2

N2P2 > N3P3

and so on….

But it’s summer time and I’m off duty…

But I do have a point.  The Top Grossing Games includes games that are less popular, but more expensive!  So it seems there is no point to this list.  So WTF WTH Apple? Why do you even have the category Top Grossing Games?  I have a theory but I will leave that for a future post.  What do you think?

Math for Bank Robbers: Part I

Does crime pay?

A pair of British economists analyzed data from 364 bank heists in the UK to answer that question.

After converting to US Dollars the average heist nets $31,600. Split between the average 1.6 robbers, each person gets $19,700. (BTW, the standard deviation is $83,000. So a lot earned around $20K and a few earned A LOT more.)  Roughly one-third of all heists end with the robbers earning nothing.  And about 20% end in the capture of the robbers.  (After 4 heists the odds of capture go up to 59%.)

So you might want to rethink a career as a bank robber.  Even if you hit 4 banks a year you’re making less than $80K and you will probably get caught.  (Which means they would confiscate any earnings you haven’t spent…)

Is it better for US bank robbers?

No, it’s worse. The average heist in the US only nets $4,330.

The only criminals making money at the banks are the bankers.