2a.-2t.
/**
 * Home Problems 2a.-2t.
 *
 * @author William Shi
 * @version V1 9/10/2014
 */
public class Evaluation
{
    public static void main(String[] args)
        {
            System.out.println(2+3*4-6);
            System.out.println(14/7*2+30/5+1);
            System.out.println((12+3) / 4*2);
            System.out.println((238%10+3)%7);
            System.out.println((18-7) * (43%10));
            System.out.println(2+19%5-(11*(5/2)));
            System.out.println(813%100/3+2.4);
            System.out.println(26%10%4*3);
            System.out.println(22+4*2);
            System.out.println(23%8%3);
            System.out.println(12-2-3);
            System.out.println(6/2+7/3);
            System.out.println(6*7%4);
            System.out.println(3*4+2*3);
            System.out.println(177%100%10/2);
            System.out.println(89%(5+5) %5);
            System.out.println(392/10%10/2);
            System.out.println(8*2-7/4);
            System.out.println(37%20%3*4);
            System.out.println(17%10/4);
    }
}
4a-4m.
/**
 * Homework problems 4a-4m
 *
 * @author William Shi
 * @version v1 9/10/2015
 */
public class Trace
{
    public static void main(String[] args)
        {
            System.out.println(2+2+3+4);
            System.out.println("2+2"+3+4);
            System.out.println(2+"2+3" +4);
            System.out.println(3+4+"2+2");
            System.out.println("2+2" +(3+4));
            System.out.println("hello 34" + 2*4);
            System.out.println(2+"(int) 2.0"+2*2+2);
            System.out.println(4+1+9+"."+(-3+10) + 11/3);
            System.out.println(8+6*-2+4+"0"+(2+5));
            System.out.println(1+1+"8-2"+(8-2)+1+1);
            System.out.println(5+2+"(1+1)"+4+2*3);
            System.out.println("1"+2+3+"4"+5*6+"7"+(8+9));
        }
}
6.
/**
 * Homework problem #6
 *
 * @author William Shi
 * @version v1 9/11/2015
 */
public class Personal
{
   public static void main(String[] args)
    {
        int age;
        double height;
        double weight;
        char gender;
    }
}
8.number%10
10.number-(number%10)
10b. number-(number%100)
12.first= 8
   second=8
14.
i= 4
j= 2
k= 1
16.double y = x * (x * x * ((x * 12.3 - 9.1) + 19.3) - 4.6) + 34.2;