Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the 10. If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.
The probability of not choosing a king after you've chosen the first king is 48/51 since there are 48 cards in the deck that are not kings and there are 51 cards left in the deck, including king cards.
