Ups and downs Problem

Question

Angie got on the elevator 3 floors above the ground floor and rode up 4 floors. She got off there, got on again and rode down to the ground floor. She forgot her umbrella and returned to the seventh floor, picked it up and rode back to the ground floor. Write an expression to show the amount that Angie rode up and down during her elevator ride. Start with the third floor as the first number.

Answer 1

Hi H.K.,

This problem is all about translation of verbal descriptions into numbers. In algebra, you will do this for variables as well.

First stop: "three floors above ground"

That translates to "3" since we assume ground is 0.

First term in expression is: 3

"Rode up 4 floors"

That translates to: 3--where she started--+4

Expression is now: 3 + 4

"Got off there, got on again, and rode down to ground floor."

3+4=7, so she's on 7th floor where she exits and re-enters, then goes down 7 levels to ground, so expression is now:

3 + 4 - 7

"She forgot her umbrella and returned to the seventh floor"

That means she went up 7 floors, which translates to "+7," so:

3 + 4 - 7 + 7

"Picked it up and rode back to the ground floor."

This is 7 floors down, so a -7:

3 + 4 - 7 + 7 - 7

This is your final expression, though net distance travelled ultimately comes to 0. I hope this helps.