Where Are the Bags of Chips?
of   =   //

of does not become //
if stressed, or if it is not followed by another word.
 

Example:  Is it 3:00?
                 No, it's ten of.

Careful (Slow) Pronunciation Relaxed (Fast) Pronunciation
JULIE: The party's tonight. I've invited a lot of people. JULIE: The party's tonight. I've invited a lot of people.
SHOKO: Then let's go shopping. It's already a quarter of three. SHOKO: Then let's go shopping. It's already a quarter of three.
JULIE: You're right. It's late. Let's make a list. JULIE: You're right. It's late. Let's make a list.
SHOKO: Okay. We need some bottles of Coke. SHOKO: Okay. We need some bottles of Coke.
JULIE:  Right. We also need a bag of pretzels. JULIE:  Right. We also need a bag of pretzels.
SHOKO: What about a few bags of chips? SHOKO: What about a few bags of chips?
JULIE:  Okay. An a couple of packages of cheese for the dip. JULIE:  Okay. An a couple of packages of cheese for the dip.
SHOKO: Great. Your cheese dips are always so good. SHOKO: Great. Your cheese dips are always so good.
JULIE:  Thanks. We need a couple of other things, too. JULIE:  Thanks. We need a couple of other things, too.
SHOKO:  Wait. I don't have my credit card. Do you have yours? SHOKO:  Wait. I don't have my credit card. Do you have yours?