Number tricks
Ask a friend if she has a “lucky number.” (It can be any number from 1
to 9.) Let’s say her lucky number is 6. Tell her that you can show her
how to get a whole row of sixes. Here’s how:
Have her multiply her lucky number by 9. When she multiplies 6 by 9,
she’ll get 54. Next, tell her to write the numerals from 1 to 9, but
without 8. She should then multiply the number 12345679 by 54. And this
is what she’ll see:
This trick will work with any number from 1 to 9. Try it and see for
yourself.
Here is a puzzle you can have fun with:
On January 1, a girl said to a boy, “Two days ago I was seven, but next
year I’ll be tenI” She was telling the truth. Try to figure out how this
could be possible before you read on.
Here’s the way it works: Two days before January 1 would be December 30.
On that day, the girl was seven. The next day, December 31, was her
birthday. On that day, she was eight. When she spoke to the boy, it was
January 1 of a new year. On December 31 of that year she would be
nine. On December 31 of the next year, she would be ten. That’s how
she could be seven two days ago and ten the next year.
Here’s another trick you can use to amaze your friends.
Tell a friend to pick any number, but he is not to tell you what it is.
You will tell him!
Have him multiply the number by 2. Then tell him to multiply the answer
by 5. Now ask him to tell you that answer. And when he does, you tell
him the number he picked!
This is how you do it: Suppose your friend picks the number 25. When he
multiplies 25 by 2, he’ll get 50. And when he multiplies 50 by 5, he’ll
get 250. When he tells you the answer, all you have to do is drop the
last numeral (in this case, 0) and you have 25—the number your friend
started with!
