A sample of nitrogen gas is kept in a 3.5-liter container at a pressure of 4 kPa. If the gas is transferred to a 7-liter container without any temperature change, what will be the new pressure in kPa? Additionally, if the pressure of the gas in the original container is written in a three-digit format (including trailing zeros if needed), how many times does the digit '0' appear? Let's think step by step and output the final answer within \boxed{}.
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