A math problem

Teacher: OK, class. If Martin has three apples, and Stacey has four, how many apples do they have together?

Donny: Six!

Teacher: Sorry, Donny, that’s incorrect. Does anyone else have the answer?

Joey: Seven.

Teacher: Very good, Joey.

Donny: Hey! That’s not fair! Why did you say Joey was right, and I was wrong?

Teacher: Because he was right, Donny. Three plus four equals seven.

Donny: But I say there’s six!

Teacher: But there are seven.

Donny: I don’t want there to be seven apples. I want six!

Teacher: But Donny, it doesn’t matter how many apples you want. There are seven.

Donny: I don’t believe you!

Teacher: Look, I have some apples right here in this basket. Let’s count them together, OK?

Donny: OK?

Teacher: First, let’s take out three apples for Martin, one…two…three. You see them, Donny?

Donny: Uh-huh.

Teacher: Now, let’s take out four apples for Stacey, one…two…three…four. You see those, Donny?

Donny: Uh-huh.