11+7

I got a new cell phone
If only I didn't have to pay
'Cause then I could have called my mom,
on that school day.
I had to call her for something important
I got out of the classroom just to do that
11+7
What is the answer? 
What is the answer!
The teacher called on me that day
And I ran out of fingers
If only I didn't have to pay.