Stuffing twenty cats in a Box

Mommy: What is this number?
Kristine: Twenty!
Mommy: Alright. Draw twenty things in that box.
Kristine: OK

Mommy: What are you doing? Just draw squares is enough
Kristine: But I want to draw cats, Mommy.
Mommy: This will take whole night, you know.
Kristine: I like cats, Mommy.

Mommy went out of the room.

Me: So, what are you doing?
Kristine: Draw cats
Me: How many cats you have drawn?
Kristine: One... two... three... four... five... six... seven!

Me: How many cats more you need to draw?
Kristine: ..... Seven!
Me: No, there ware twenty cats and you only drew seven. So, how many more cats do you need to draw?
Kristine: Um.......
Me: You need to draw another thirteen
Kristine: .............. (thinking hard and then realised the amount of work)

Kristine: Can I draw squares, Daddy?
Me: No, you started with cats, so you must finish them (heh heh)

Then Mommy came back in again,
Mommy: Whai! You still drawing cats, ah?