# The Harmony Learning Community Blog

News, Updates, Program Recaps, and Homeschooling Information

### Category Theory 1: Odd One Out

(October 25, 2018) An important concept in category theory, indeed in mathematics itself, is deciding which attributes to ignore when you conduct mathematics. Context matters. When you’re signing a contract to buy a car, you may not care what color the contract is printed on. But when you’re sending out your wedding invitations, you might care about the paper color…

### OPEN Q’s #6: Liar’s Dice

(May 26, 2016)  Split into 3 teams.  Each team gets 5 dice.  Roll them all, look at them, but don’t let the other team see them.  The first team makes a 2-digit bid.  The first digit of the bid is your prediction of the total number of dice of a certain value every team combined has.  The second digit is…

### COMPASS ART 1: Intro to Geometry

(September 17, 2015)  Our new math circle course on compass art for 9-11 year olds began with a switcheroo activity:  I gave everyone a printout of an image, and about every 30 seconds said “switch!”  I asked them to pass their page clockwise one person.  The images included: Mandalas from various traditions (Celtic, etc), Zarah Hussein’s Islamic art, Native American…

### Math Circle Blog: Infinity, the Prime Directive, and Perplexity

It’s Good to be Perplexed in Math N came up to the board a number of times as we continued last week’s probability problem.*  D had planned to start class with a new approach, but didn’t because his ideas had changed over the week.  N first came up to question the possibility of actually choosing chords randomly.  He suggested an…

### Math Circle Blog: The Popcorn Problem

Geometry, arithmetic, optimization, logic, and question asking. SEPTEMBER 18, 2012: “What would it take to fill this room with popcorn?” “a big popcorn machine” “the machine running a long time” “a lot of patience” “corn, heat, oil” “a small factory” “a lot of people” At this point in this term’s first math circle, participants began to debate whether these things…