spoken:

Okay, all you cats 'n kiddies, it's time for a little addition! Can you dig it?! Here we go! Now ...

sung:

Adding is putting together, hmmm
Adding is just what you do
If I have one cookie and you have one cookie
Together they add up to two
One cookie and one cookie makes two cookies
One and one is two
That's two, whoo!

Yeah, outta sight!

Adding is putting together, hmmm
And I'm sure you will agree, yeah
If you have two cookies and I have one cookie
Together they add up to three
Two cookies and one cookie make three cookies
Two and one is three, oh!

Dig it! Hmm-hmm

Adding is putting together, hmmm
Adding is making it more
If you have three cookies, add one more cookie
This time the answer is four
Three cookies and one cookie make four cookies
Three and one is four, whoo!

Cookie Monster: Hey, cookies! Hey, what you doing?

Hippie: Singing about addition.

Cookie Monster: Why you not sing about subtraction?

Hippie: Subtraction?

Cookie Monster: Yeah, sure. I'll show you.

Subtracting is taking away from, hohooh
Subtraction is my kind of fun (now listen, see)
When you have four cookies and I see four cookies
I subtract them and leave you with none (haha, now see this)
Four cookies minus four cookies is no cookies, ha
And now my song is done

And so are the cookies! (sounds of Cookie Monster eating)

Both: Oh yeah!!!!

Hippie: Outta sight!

Cookie Monster: Yeah!