Top Posts
 "Ontogeny recapitulates phylogeny" in math education
 Notes on Lookup  A Sieve for the Collatz Problem
 Notes on Lookup  Histograms as Sieves
 Notes on Lookup  Another Sieve for the Collatz Problem
 A CollatzInspired Puzzle
 Groupings, Shopping Lists, Vectors: part 14
 Notes on Lookup  Computation versus Lookup in School
 Notes on Lookup  Eratosthenes and Other Sieves
 Operators, Functions, and Properties  part 29
 Notes on Representation  Tally Marks

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 Mathematical Notations and Schools – 15
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 Mathematical Notation and Schools – 2
 Mathematical Notation and Schools: The Series
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Tag Archives: puzzle
What is Multiplication – part X
Yesterday, in the supermarket, a customer dumped a whole basket full of power bars on the counter. The checkout counter person started to scan them in, one by one. After seeing about seven of them scanned, with a lot more … Continue reading
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Tagged denominations, math class, models, puzzle, representations, reverse engineering, unlearning
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Math in the Comics – part 10
From last week’s Foxtrot comic, another take at the cultural background conversation of math. Who is bad at math? At one level, a puzzle. The top part, the part that starts with “1611135” is not a subtraction problem. It is … Continue reading
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Tagged gauntlet, graded hurdles, math class, math in the comics, puzzle, selection
2 Comments
A CollatzInspired Puzzle
This is a puzzle. In prior posts, I used the Collatz Problem, restated here: Each counting number n past 1 is assigned a successor number, as follows: The number “1″ is considered home, and when you’re home, you stop. If … Continue reading
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Tagged models, puzzle, recurrence relationship, representations, reverse engineering
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Mathematical Puzzle – Hinges
This is a puzzle. Imagine I have three rods of length 1 each, and they are connected together with perfect hinges. Together, they form a somewhat flexible shape ABCD (with AB=1, BC=1 and CD=1), even if I fix the two … Continue reading
Math in the Comics – part 2
Today, Bill Amend has another comic strip with math in it: It plays on the Fibonacci series, which these two geeks obviously know well. The starting numbers of the Fibonacci series are 1, 1, 2, 3, 5, 8, … and … Continue reading
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Tagged extending patterns, math in the comics, puzzle, recurrence relationship, reverse engineering
2 Comments
Notes on Divisibility – Common Divisors
In an earlier post I introduced the notion of a divisor without relying on division, instead thinking of it as a mark that was left during skip counting. This is a very old notion, dating at least to the times … Continue reading
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Tagged denominations, extending patterns, lookup, models, naming, puzzle, reverse engineering
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Powerful Sunglasses
This is a puzzle. Imagine I own a pair of sunglasses that reliably blocks ultraviolet rays so that, out of any ten rays that shine on it, only one of them gets through. So, if 40 rays shine on them, … Continue reading