if bob has 3 blue shirts and rob has 4, how many do they have in all?

I must say, I love the take on this.

 

Not many people will take the time to dissect questions like this, much less reply with a question. This just goes to show how very different disciplines such as linguistics and math can still overlap:)

You have to add 3 and 4, like this:

$${\mathtt{3}}{\mathtt{\,\small\textbf+\,}}{\mathtt{4}} = {\mathtt{7}}$$

Actually, you said "if bob has 3 blue shirts and rob has 4, how many do they have in all?". so this is what we know:

- Bob has 3 BLUE shirts.

- Rob has 4 (4 what? Four as in Tobias from Divergent?)

Plus, you spelled a NAME with a uncapitalized letter so, i asume you meant to say robber instead of Rob.

And, you said "how many do they have in all?" how many what? How many numbers are in this question?

But you also said IF bob has 3 blue shirts. IF he doesn't, what is the meaning of this question?

So the question actually is "IF bob has 3 blue shirts and a robber has Four (Tobias), how many numbers would they have in this question?"

And thus, the anwser is either

1; because IF bob, being the irresponible person he is, forgets to bring his 3 shirts for counting, and the robber brought Four, there would only be Tobias/Four standing alone.

or

2; because lets say bob remembers to bring the 3 shirts, so in the question, there would be 2 numbers; 3 and Four.

NOW, the real question is: How many times did I say a number in this answer? 

Do I mean the word 'number' or number as in digits?

You will never know.

GRAMMAR, SON!