Answers 399- DOMINO HOLLOW SQUARES
It is shown in the illustration how the 28 dominoes may be arranged in the
form of7 hollow squares, so that the pips in the four sides of every square add
up alike. It is well to remember this little rule when forming your squares. If
the pips on your dominoes sum, say, to 7 (as in the first example), and you
wish the sides to add up 3, then 4 X 3 - 7 gives us 5 as the sum of the four
comers. This is absolutely necessary. Thus, in the last example, 4 X 16 =
64 - 43 tells us that the four comers must sum to 21, as it will be found they do.
- DOMINO SEQUENCES
If we draw from the set the four dominoes 7-6, 5-4, 3-2, 1-0, the remain-
ing dominoes may be put together in proper sequence. Any other combinations
of these particular numbers would do equally well; thus we might withdraw
7-0,6-1,5-2, and 4-3. Generally, for any set of dominoes ending in a double
odd number, those withdrawn must contain together every number once from
blank up to two less than the highest number in the set.- TWO DOMINO SQUARES
The illustration on page 400 shows how the twenty-eight dominoes may be
laid out so as to form the two required squares with the pips in each of the
eight sides summing to 22. With 22 as the constant sum, the comers must sum