Posts Tagged ‘mathematics’

General problem 2I went to the local pizzeria on a recent Saturday night. The cost was $10.50; I gave the cashier a $20 bill and a $1 bill. But he gave me back the dollar bill, and then gave me change for the $20, which was $9.50.

As it turned out, they were out of five-dollar bills Read the rest of this entry »

The first time I ever even had a passing interest in soccer was watching some eight-year olds play in the early 1980s. Now my daughter has participated the last couple years, so I’ve become vaguely informed about the nuances. The Daughter wants one of those new soccer balls, called a brazuca, but I hear it costs $160; not happening.

Not that I would dis anyone who didn’t like the sport because they thought it was boring; I used to think so myself. But I figuratively rolled my eyes at certain Americans with their observations. Read the rest of this entry »

rjcoldfact
New album from Rebecca Jade & The Cold Fact the debut release from San Diego-based eclectic soul/funk band. RJ is my niece, my sister Leslie’s daughter.
From NBC San Diego: “Not everything on April Fool’s Day was a joke. Rebecca Jade & the Cold Fact released their self-titled debut and it’s no laughing matter. Channeling everyone from Candi Staton and Betty Davis to Morcheeba and Brightback Morning Light, these 12 tracks of soul and funk are stunners. Do yourself a favor and pick up a copy.”
Another review.
In this picture, she’s the one in the blue dress.

After watching this video, I’m even more convinced than I was before: Daylight Saving Time is a waste of time. Having tried to schedule a phone call from the UK at a point when the US is in DST and the UK has NOT yet moved to British Summer Time, I know of which the speaker is talking about.
Read the rest of this entry »

Zero has fascinated me for-practically-ever. I saw this article in BoingBoing, which led to this piece in the Guardian:

“Only [India] introduced a symbol, 0, and treated it as if it was a normal digit just like all the others from 1 to 9. Invention of the number zero was possibly the greatest conceptual leap in the history of mathematics.

“But why did the Indians make this leap and not China or Babylon? …

“India made another contribution to world culture as well as zero: the idea of nirvana, the transcendent state of “nothingness”, when you are liberated from suffering and desires.

“In fact, the word used in philosophical texts to mean nothing, or the void, is “shunya”, the same word later used to mean zero.
Read the rest of this entry »

I have this friend Bruce who turned 70 late last year. I’ve only known him about a decade, so I didn’t know him when he was raising his children. At his party, I learned that one of the primary messages to his kids was that “math is everywhere.” I definitely believe that.

I’ve been hooked on numbers ever since I realized that if you add up the digits in a long number and the total adds up to 9, the number is divisible by 9. Obviously that same number, if even, is divisible by 18. If it ends with a 5, is divisible by 45, and if it ends with a zero, is divisible by 90. My daughter thinks multiplying by 9 is cool too. You multiply by 10, then subtract the number you multiplied by. So 7X9=7X10-7X1=70-7=63.

I was also fascinated that 5X5=25 and 6X4=24, 6X6=36 and 7X5=35, et al. Thus Y squared =(Y+1) (Y-1) +1. So I know if 123 squared=15129, then I know that 124×122=15128. My daughter is starting to figure this out, too.

Speaking of The Daughter, this problem in her third grade math homework really bugged me. Read the rest of this entry »

Contact me
  • E-mail Contact E-mail; Blog content c 2005-2018, Roger Green, unless otherwise stated. Quotes used per fair use. Some content, including many graphics, in the public domain.
  • Privacy policy Privacy policy of this blog
I Actually Know These Folks
I contribute to these blogs
Other people's blogs
Politics
Popular culture
Useful stuff
May 2018
S M T W T F S
« Apr    
 12345
6789101112
13141516171819
20212223242526
2728293031  
Archives
Counter
wordpress analytics