Which order should I add numbers in?

NARRATOR: Hello Snoot. Hello Fin.

BOTH: (ALIEN LANGUAGE)

NARRATOR: I see you’re at the space station.

Have you come to see the space ships?

SNOOT: (ALIEN LANGUAGE)

NARRATOR: How exciting! How many space ships can you see?

That’s 1… 2… 3… 4 shuttles in the service area, 1… 2… 3 rockets in the docking bay and 1… 2 flying saucers in the loading area.

What a lot of different ships.

How many are there altogether?

SNOOT: Er… Oo…

NARRATOR: Why don’t you start by adding the 4 shuttles and the 3 rockets?

4 add 3 equals 7.

Then take that 7 and add the 2 flying saucers.

7 add 2 equals 9.

FIN: (ALIEN LANGUAGE)

NARRATOR: Alright Fin, if you’ve got another way of counting them up, be our guest.

Ah, I see.

You prefer to start by adding the 2 flying saucers and the 3 rockets.

2 add 3 equals 5.

Then we take that 5 and add the 4 shuttles.

5 add 4 equals 9 as well.

BOTH: Aha!

NARRATOR: That’s right, it doesn’t matter which pair of numbers you add together first: you could do 4 add 3 add 2, or 2 add 3 add 4, the answer’s just the same.

SNOOT: (ALIEN LANGUAGE)

NARRATOR: What’s that Snoot?

(LAZER SHOTS FIRED)

More space ships?

Oh dear, intergalactic raiders.

I think we may have lost one or two ships…