# Category Archives: game

## Towers of Hanoi Proof

This is the Towers of Hanoi. The puzzle is almost intuitive: how can you move the tower from the left peg to the right without placing any larger disks on top of any smaller disks.   Wikipedia has this animated … Continue reading

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## The Dr Square Puzzle Part II

(Click here for part I) Recall the puzzle: Step 1: Choose a starting number. Step 2: Square the number. Step 3: Sum up the digits of that number. Step 4: Repeat steps 2 and 3 until you understand what’s going … Continue reading

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## The Dr Square Puzzle

One of my students yesterday shared an idea with me that he had kicking around in his head for a while, which he called continued multiplication. Essentially, he used the steps in a multiplication process as an iterative process to … Continue reading

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## Josekis

What is joseki? It’s a handy word, and used frequently in Japan. A remark overheard one clear morning: ‘I’m going to follow my joseki and take the dog out for a walk.’ … These days the word ‘joseki’ has come … Continue reading

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## Squares of Differences III: a surprising solution

[See Squares of Differences I and Squares of Differences II, and apologies for the tardiness of the posting] I’ve learned a lot about Squares of Difference in the last months. First, they’re sometimes known as Difference Boxes, or Diffy Boxes, … Continue reading

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## Numberplay at the New York Times Puzzle Blog

Katherine submitted the puzzle for this week’s Numberplay at the New York Times Puzzle Blog, a lovely puzzle in honor of Avoid Triangles At All Costs (ATAAC) Day. So… 1. Check it out here! 2. Comment! We (and the people … Continue reading

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## Squares of Differences II: Changing Direction

[Note: this is a continuation to the first Squares of Differences post. Read that before continuing.] A week after introducing her class to squares of differences (see  for the first post on this lesson), one of Katherine’s students walked in … Continue reading

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## Squares of Differences: subtraction practice toward a greater purpose

Here is a phenomenal lesson, accessible to any child who knows how to subtract, and compelling to everyone, up to and including professional mathematicians. Get a kid engaged in it, and they’ll do hundreds of subtraction problems without complaint, because … Continue reading

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## Hex Board!

If you read about the amazing gift of the (now consumed) Sierpinskitaschen last week, you would rightly assume that our present karma had about played itself out. Not so! On Tuesday I had two students–third graders at an after school … Continue reading

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## Family Math: my new favorite book for parents and young kids

I just got it last evening, and I’ve got to say, Family Math is almost perfect. Their advice to parents: dead on. Like, Let [your children] see you enjoying the activities, liking mathematics… if a parent says “You know, this … Continue reading

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