- algorithm
- approximation
- bar
- binary
- binomial coefficients
- book
- cards
- carnival
- Carnival of Mathematics
- chocolate
- circle
- coins
- combinatorics
- complex
- conjecture
- convolution
- counting
- decadic
- decimal
- diagrams
- Dirichlet
- Euler
- factorization
- Fermat
- fibonacci
- game
- games
- gcd
- graph
- groups
- Haskell
- integers
- irrational
- Ivan Niven
- Lagrange
- lehmer
- little
- lucas
- MaBloWriMo
- making
- Mersenne
- moebius
- mu
- nim
- number
- numbers
- objects
- omega
- order
- pi
- powers
- prime
- primes
- primitive
- programming
- proof
- puzzle
- review
- roots
- sequence
- square
- strategy
- sum
- symmetry
- test
- theorem
- tree
- triangular
- two-player
- unit
- unity
- video
- visualization
- X
- zero-sum

### Blogroll

### Fun

### Reference

### Categories

- algebra (46)
- arithmetic (63)
- books (29)
- calculus (7)
- challenges (53)
- combinatorics (14)
- complex numbers (6)
- computation (47)
- convergence (9)
- counting (32)
- famous numbers (48)
- fibonacci (18)
- fractals (13)
- games (34)
- geometry (57)
- golden ratio (8)
- group theory (27)
- humor (6)
- induction (7)
- infinity (19)
- iteration (24)
- links (74)
- logic (6)
- meta (42)
- modular arithmetic (24)
- number theory (85)
- open problems (11)
- paradox (1)
- pascal's triangle (8)
- pattern (92)
- people (21)
- pictures (70)
- posts without words (26)
- primes (44)
- probability (6)
- programming (17)
- proof (74)
- puzzles (15)
- recursion (16)
- review (20)
- sequences (28)
- solutions (28)
- teaching (14)
- trig (3)
- Uncategorized (6)
- video (19)

### Archives

- January 2018 (2)
- December 2017 (3)
- November 2017 (3)
- October 2017 (1)
- September 2017 (1)
- July 2017 (4)
- June 2017 (4)
- May 2017 (9)
- April 2017 (7)
- March 2017 (5)
- February 2017 (4)
- January 2017 (3)
- December 2016 (4)
- November 2016 (6)
- October 2016 (6)
- September 2016 (2)
- August 2016 (5)
- July 2016 (2)
- June 2016 (4)
- May 2016 (4)
- April 2016 (2)
- March 2016 (3)
- February 2016 (9)
- January 2016 (8)
- December 2015 (5)
- November 2015 (29)
- August 2015 (3)
- June 2015 (2)
- April 2015 (1)
- May 2014 (1)
- December 2013 (1)
- October 2013 (1)
- July 2013 (1)
- June 2013 (1)
- May 2013 (1)
- April 2013 (3)
- March 2013 (3)
- February 2013 (2)
- January 2013 (5)
- December 2012 (3)
- November 2012 (4)
- October 2012 (5)
- September 2012 (1)
- August 2012 (4)
- July 2012 (1)
- June 2012 (6)
- May 2012 (2)
- April 2012 (3)
- March 2012 (1)
- February 2012 (4)
- January 2012 (5)
- December 2011 (1)
- November 2011 (7)
- October 2011 (4)
- September 2011 (6)
- July 2011 (2)
- June 2011 (4)
- May 2011 (5)
- April 2011 (2)
- March 2011 (4)
- February 2011 (1)
- January 2011 (1)
- December 2010 (1)
- November 2010 (4)
- October 2010 (2)
- September 2010 (1)
- August 2010 (1)
- July 2010 (1)
- June 2010 (2)
- May 2010 (3)
- April 2010 (1)
- February 2010 (6)
- January 2010 (3)
- December 2009 (8)
- November 2009 (7)
- October 2009 (3)
- September 2009 (3)
- August 2009 (1)
- June 2009 (4)
- May 2009 (5)
- April 2009 (4)
- March 2009 (2)
- February 2009 (1)
- January 2009 (7)
- December 2008 (1)
- October 2008 (2)
- September 2008 (7)
- August 2008 (1)
- July 2008 (1)
- June 2008 (1)
- April 2008 (5)
- February 2008 (4)
- January 2008 (4)
- December 2007 (3)
- November 2007 (12)
- October 2007 (2)
- September 2007 (4)
- August 2007 (3)
- July 2007 (1)
- June 2007 (3)
- May 2007 (1)
- April 2007 (4)
- March 2007 (3)
- February 2007 (7)
- January 2007 (1)
- December 2006 (2)
- October 2006 (2)
- September 2006 (6)
- July 2006 (4)
- June 2006 (2)
- May 2006 (6)
- April 2006 (3)
- March 2006 (6)

### Meta

# Monthly Archives: June 2010

## Right answers for the wrong reasons

Here’s a recent xkcd which as a math educator I found particularly funny. Some questions for my readers: What numbers besides 3 and 9 would “work” here? Do you have any particularly funny or interesting stories of students getting something … Continue reading

## Optimal change-carrying

Recently Michael left the following challenge in a comment: I’ve been trying to optimize my change-carrying habits. What is the smallest amount of quarters, dimes, nickels and pennies one can carry while still being able to give perfect change (two … Continue reading