A kid called up his mum from his college and asked her for some money, because he ran out of it.  Mum said, "Sure, sweetie.  Mum will send you some money.  You also left your calculus book here when you visited 2 weeks ago. Do you want me to send that up too?"

"Uhh, oh yeah, o.k." Responded the kid.

So Mum wrapped the book along with the checks up in a package, kissed Dad goodbye, and went to the post office to mail the money and the book.

When she gets back, Dad asked, "Well how much did you give the boy this time?

Mum said, "Oh, I wrote 2 checks, one for $20, and the other for $1000 out to him"

"That's $1020!!!" yelled Dad, "Are you crazy???"

"Don't worry hon," Mum said, kissed Dad on the on top of his bald head, "I taped the $20 check to the cover of his book, but I put the $1000 one somewhere between the pages in chapter 19!"