The Sequential Number
“Lennie, have you done your math homework?” asked daddy, while driving home from school.
“Yes, daddy I did it during math class,” said Lennie with a bored expression.
“That was fast,” said daddy in surprise, “was it so easy?”
“Yes, daddy, too simplistic. Can you give me something interesting to puzzle on,” asked Lennie.
“Yes, I can: There is a four digit number with sequential digits that is divisible by seven,” said daddy with a smile. “Can you find it, Lennie.”
“Oh, thank you so much, daddy I like that one,” said Lenny enthusiastically jumping up and down on the car seat.
And Lennie worked it out before they got home.
What would you say is this number?
Tags: congruence, divisibility