november 9

• More work with vectors. Can we detect a right angle? 
• Coloring maps: when two colors are enough?
• Getting robots out of the maze, blindly
• Choosing socks again. Walking in square grid?

Experimenting with Hopscotch robots...

homework

1.  How many colors one needs to color this map?

2. On the left is shown what would happen to the green strip under the turn by 90 degrees around the red point. Draw what would happen if you turn by 90 degrees the yellow and the violet shapes?

3. One big bag and one small bag can hold 5 pumpkins, while two big bags and three small bags can hold 12 pumpkins. How many pumpkins each bag can hold?

november 2

• More bus stop placement: this time, interactive. Also - on a circular road...
• Robot in a labyrinth - interactive.
• Choosing socks and walking in Urbana - same thing?
• What floats, and how...

Homework

1. If the drawer contains 2 red, 2 blue, 2 green, 2 yellow and 3 pink socks, how many one needs to take (not looking), to have at least 3 different colors? 4 different colors?

2. How many colors one needs to color
this map of an island, so that no two countries of the same color had a common segment of boundary?
















3. Black robot understands all the commands: UP, DOWN, LEFT, RIGHT correctly, but the white one does the opposite (you say RIGHT, it goes LEFT etc). They listen to your commands and move simultaneously. Can you make them meet,

if they start from these positions?

or from these?