Can you replace the question mark with a number?

"Thanks for the harmonica you gave me for Christmas," little Joshua said to his uncle the first time he saw him after the holidays. "It's the best present I ever got."

"That's great," said his uncle. "Do you know how to play it?"

"Oh, I don't play it," the little fellow said. "My mom gives me a dollar a day not to play it during the day and my dad gives me five dollars a week not to play it at night.