Phrase "Where's my cards?"

[SkiIucK]

I am sitting in my chair, watching this "Michael Clayton" movie and all of a sudden a kid shouts at his mother "Mum, where's my cards?!" Why "is" and not "are"? Is the kid referring to the entire deck which the cards sum up into? Or it's just an improper usage of the language by the kid? Clarify please! Thank you!
Regards,
Mitko
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If you find any typographical or grammatical errors in my post, please let me know.

[Mister Micawber]

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It is common and acceptable in spoken English. First, we are often thinking of the set; second, where's is easier to pronunce than where're.
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Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mr. Micawber

[lost_soul]

[Mister Micawber]

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It is fine; it is a common contraction.
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_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mr. Micawber