Dear Booknerd, my heart is with you (you may actually find my similar question earlier in the thread). I hope this is a useful answer--every square of the crossword is to be filled with the symbol of an element (H = hydrogen, Cs = cesium, etc.). The letters spell out words, whose clues are given in the word clues. however, if you use the Atomic Number for each of these elements instead of the letters, you can add up the Atomic Numbers to get the numeric values in the number clues. Does that help, or were you already there?