How to round up the result of integer division?

For C# the solution is to cast the values to a double (as Math.Ceiling takes a double):

int nPages = (int)Math.Ceiling((double)nItems / (double)nItemsPerPage);

In java you should do the same with Math.ceil().

A generic method, whose result you can iterate over may be of interest:

public static Object[][] chunk(Object[] src, int chunkSize) {

    int overflow = src.length%chunkSize;
    int numChunks = (src.length/chunkSize) + (overflow>0?1:0);
    Object[][] dest = new Object[numChunks][];      
    for (int i=0; i<numChunks; i++) {
        dest[i] = new Object[ (i<numChunks-1 || overflow==0) ? chunkSize : overflow ];
        System.arraycopy(src, i*chunkSize, dest[i], 0, dest[i].length); 
    }
    return dest;
}