Mexican train dominoes requires a centre circle or "hub" from which each player starts her line of dominoes. The standard hub has eight spaces for players to begin their domino lines, but if you do not have eight players you can leave one line open from which anyone can play. If you make your own hub, you can use any set of dominoes preferably with 91 pieces.
Place the card stock on a table or solid surface. Using the compass, make a circle about 6 inches in diameter. This will make the hub large enough for eight domino pieces.
Using the edge of one domino, trace the outline of it on the shorter side of the piece into the circle about a half an inch. This will be the outline for where the notches will be cut out of the circle.
Trace eight total spaces with the domino, evenly spaced. This allows you to leave about a quarter an inch of space between each of the notches formed by the outlines.
Cut with the scissors along the circle marking. If you cut the circle out first, it will make the straight lines of the notches simple to cut out.
Cut the straight lines you traced from the domino heads. This will create the notch and will exactly match the head of your domino pieces.
You can trace the entire outside of a single domino in the centre of the hub if you wish. This gives a clear marker for the starting domino of the game. One alternative is to cut the circle out before you start tracing the notches. You will end up with the same squares and you might find it easier to measure.
Cutting the notches as you try to cut the circle can make the square edges uneven. It is easier to cut the entire circle first.