YOU SAID:

I would like that slice of pizza please and where is the bathroom?

INTO JAPANESE

ピザを一切れお願いします。トイレはどこですか?

BACK INTO ENGLISH

I'd like a piece of pizza, please. Where is the restroom?

INTO JAPANESE

ピザを一枚お願いします。トイレはどこですか？

BACK INTO ENGLISH

I'd like a piece of pizza, please. Where is the restroom?