Introduction
Courtney finds many puzzling things when she plays the computer game "Number Between". She interprets the decimal part of the number as the denominator of a fraction (i.e. as the number of pieces something has been divided into). She is unable to find a number between 0.45 and 0.5, because she is searching between 1/45 and 1/5.

Comments: Text in italics
Interviewer: Text in red
Courtney: Text other colour

Interviewer:
In this game you have to type a number which fits on the numberline. You can see the two endpoints on the screen. For this turn they are point 3 and point 5.

Courtney:
I think it must be point 4

Courtney thinks that 0.3 is 1/3 and 0.5 is 1/5, so the numberline is, for her, reversed, with the larger number on the left.

Interviewer:
OK, the computer has accepted your answer and now it will change the number line for your next turn.

Courtney:
But there is no number between 4 and 5! (pause)...

Interviewer:
Try point four five.

Courtney enters 0.45 and is surprised when it is accepted.

Courtney:
That's weird!

The computer presents the new numberline.

Courtney:
Now there are lots of numbers there, between 5 and 45 pieces...

Interviewer:
Just choose one of them

Courtney:
OK, that's easy, maybe 28 pieces.. so point two eight.

Computer rejects 0.28

Courtney:
This is strange... if it has to be bigger than 28...maybe 9 pieces

Since 0.28 is too small, Courtney thinks that she needs a number between 5 and 28.

Courtney's choice of 0.9 is rejected.

Courtney:
This doesn't make sense... there is something wrong with this game