Introduction
Maria does these tasks correctly and easily because only two decimal places and involved. The interview may have been more interesting if she had been asked to make numbers with more decimal places.

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

Interviewer:
I have a number that starts 3 point something something and you get to choose the rest of the number.

Interviewer:
Here are the cards to choose from...

Interviewer:
...marked 0,1,2,3,4,5,6,7,8 and 9. I'm going to ask you to make the biggest number that you can by choosing any 2 of these cards.

Maria:
OK

Maria chooses correctly

Maria:
Usually, the biggest is 99, but I couldn't use the 9 again. Anyway, with rounding at the shops $3.99 is really $4.

Interviewer:
OK, now we'll put those cards back...

Interviewer:
...and could you make another number, this time as small as you can?

Maria again chooses correctly

Interviewer:
OK, good. I guess you don't often pay that at the shops either anymore.

Maria:
Yes, sometimes rounding is good when you get to pay less, like $3.