The 24-point game is to pick any 4 cards from 52 cards, as shown in Figure 20.19.

The Jokers are excluded. Each card represents a number. An Ace, King, Queen, and Jack represent 1, 13, 12, and 11, respectively. You can click the Shuffle button to get four new cards. Enter an expression that uses the four numbers from the four selected cards. Each number must be used once and only once. You can use the operators (addition, subtraction, multiplication, and division) and parentheses in the expression. The expression must evaluate to 24. After entering the expression, click the Verify button to check whether the numbers in the expression are currently selected and whether the result of the expression is correct. Display the verification in a label before the Shuffle button. Assume that images are stored in files named 1.png, 2.png, . . . , 52.png, in the order of spades, hearts, diamonds, and clubs. So, the first 13 images are for spades 1, 2, 3, . . . , and 13.

|Exerdse20_13 |Exercise 20_13 |x| The numbers in the expression don't match the numbers in the set Shuffle Correct Shuffle Enter an expression: (11/ 11 + 2) * 8 Verify Enter an expression: 3 + 4 +5+ 5 Verify |Exercise 20_13 - lo|x| Incorrect result Shuffle Enter an expression: (11/ 11 + 2) + 8 Verify FIGURE 20.19 The user enters an expression consisting of the numbers in the cards and clicks the Verify button to check the answer.