Doctor Who (2005)

Voyage of the Damned - S3-E16

Question: I just wanted to check before I post it as a mistake. When Morvin and Foon are fixing the Host, Foon says she spent 5000 credits on phone calls and that they'll never be able to pay it off. At the end of the episode, the Doctor tells Mr. Copper that he has 50,000,056 credits on his card which he says is equal to £1,000,000. According to this calculation, the 5000 credits that Foon spent, divided by 50.000056 = £99.999888. Surely even though they work on a milk market they'd be able to pay that off easily, wouldn't they