How this goes in real life: "Was your number... 3741?" "No." "Heh, I'm afraid that's impossible based on number theory. You must have made a mistake in the s

How this goes in real life: "Was your number... 3741?" "No." "Heh, I'm afraid that's impossible based on number theory. You must have made a mistake in the step where I asked you to choose a second 4-digit number by scrambling the four digits of the first number and subtracting the larger number from the smaller. Try it again, I'll wait." "No."