"How do?" came a greeting somewhere above Baby.
Baby looked up to see a large toy snake.
"Hello, snake" said Baby, "I suppose you are an adder?"
"Why no", said the snake, "I'm Binary Bill, the snake that can tell you which day you were born on without you telling me..."
All I have to do then is to add the numbers in the top left hand corner of the cards you have picked out to say correctly what day you were born on."
"O.K." said Baby "my cards are A, C and E."
"That's 8 (card A) + 4 (card C) + 2 (card E). 8 + 4 + 2 =14. Your birthday is the 14th!" said Bill.
"Wow! That's right." said Baby.
"Can you work out my birthday?" asked Bill, "my cards are A, B and E."
Try to work out Bill's birthday. If you want to check if you are right or you want to know how it works click on the snake in the picture.
Click on the moon to go to the next place...
...or click on the star to go back to the start