april 27

A dragon eats for breakfast an apple and a boar. A unicorn eats for breakfast 2 apples. Some number of unicorns and dragons met for breakfast and ate three boars and seven apples. How many dragons and unicorns met?

Same question for five boars and eight apples. OK, nine apples. For which numbers this puzzle has an answer?

Pete goes from Champaign to Savoy (6 miles), making 2 miles per hour. Slow Joe goes from Savoy to Champaign, on the same road, making 1 mile per hour. How far from Champaign will they meet?

Graph paper and rulers. Coordinate axes. Place points. Are the three points on one line?

Straight line on graph paper: can it cross first two horizontal then two vertical bars? Write down sequences you see (VHHV, as an example).

april 20

Pascal triangle mod 2 (did not work, return later)

More Chinese reminders

Game with stickers on forehead: each reports how many blue/red stickers they see; define their own color. Two stickers?

Graph paper and rulers. Coordinate axes.
Place points. Are the three points on one line?

april 13

Add numbers separated by two. Is the result always even? Add three numbers separated by two... What now?

More Chinese reminders

Game with stickers on forehead: each reports how many blue/red stickers they see; define their own color. Two stickers?

Graph paper and rulers. Coordinate axes.
Place points. Are the three points on one line?

Digital straight line: draw line; see how the horizontal/vertical bars are intersected. Is there a pattern?

Unknot an unknot

copper tube experiment

4.6

Add neighboring numbers: why the result is always odd?
Add three neighboring numbers: what it is divisible by?
What about four neighboring numbers?

Pascal triangle mod 2

Post-it puzzle: Alice, Bob and Claire see the others' numbers, not theirs. Alice sees 3, Bob 3, Claire 2. What numbers each has?

Same with kids

Hedgehog wants to bring an apple to the porcupine, and return back

SET

Disentangle