Playfair cipher

This is the link to the playfair cipher:

http://en.wikipedia.org/wiki/Playfair_cipher

You should first try to encrypt  the word "rabbit" with the keyword "playfair example" . REMEMBER: I=J ! 
You should get ELGIKBWI. Isn't this code cool?

A family

My daughter is twice as old as my son.
And I'm twice as old as my daughter.
In 22 years I'll be twice as old as my son.
How old is everyone in our family?

What color is the bear?

You start at a certain point. You go 20m. south, 20m. west, and 20m.north. You come to the same place where you started from. Then you meet a bear. What color is the bear?

Family in the attic

A family consisting of a boy Matti, his dad, his little sister and their grandma needs to get down from the attic before the roof falls in. The stairs are dark and they have only one flashlight and can't go down the stairs by more than 2 people at a time. They have 18 minutes altogether. For Matti it takes 2 minutes to go up or down the stairs, for dad 3 minutes, for little sister 5 and for grandma 7. How can they make it?

Brain teaser: what does "EGG + EGG" give you?

(The answer is: a PAGE!)

This is a reverse cryptogram. You must figure out what number is represented by each letter in the problem below:

EGG + EGG = PAGE

(From www.kidzone.ws/math)

Fractions: a puzzle or a lotto?

The club teachers provided a superb visual training on fractions in form of a puzzle-lotto-like game (for which they spend many hours at home to prepare the material!)

Each student got a set of 5 circles to fill. Then there were a lot of multicolored parts available (1/2, 1/4, 1/8, 1/16). And each group of 5 kids had a dice to share. The dices were all different and they contained pictures of different fractions on each side (2/2, 3/8, 5/16, etc).


Tasks:
1. Get the own set of 5 wholes (circles) filled as soon as possible by throwing the dice in turns and getting the indicated fraction from the pool of the parts.
2. Given a random set of fractions (parts), how many wholes can one assemble?

Tower of Hanoi

A small Tower of Hanoi with 3 disks.