Three of Pentacles

    The theme of this card is manifesting a goal through teamwork, planning, and competence. Another take is creativity and expansion. This is the earliest form of manifesting, like a plan is coming together, but not complete. It is the base thought on the triskele, a powerful Celtic sigil.
     In magical applications, there are several ways this is significant. Most Goddesses (or Gods) have three aspects. For example, when I go to Hecate, She comes sometimes as a Maiden, kind of like a big sister, sometimes as Mother, kind and understanding, and sometimes as Crone, old and wise.
     In creation, when Deity made two circles, the thought was in place to make two spheres, but just then creation was in two dimensions. With the creation of three, now there can be three dimensions. Drawn on paper, two circles with the circumference joined to the origin of each other. Adding a third origin, just where the circles meet, and making a third circle both makes a triangle, and illustrates the trinity. Now we have a masculine, a feminine, and a spirit. This will not be the end, but it is enough for now. Joining the dots makes a triangle. This is the first of many, the triangle of fire. We could say others, but this is the first time of change, and fire is the agent of change. Things will be put into order later. In our new found three dimensions, we have the three sided pyramid of fire, a platonic solid. Both up and down. The three dimensional vessica is now divided in half, by having a third sphere through it. It still works as before, but there is a new meaning to part of the creation. 
      Mathematically, now we have a next step in the series. First there was 1, then 1+1=2, now 1+2=3. The series is growing. Here, it is too soon to tell, but this is the basic pattern upon which all life grows. An embryo is one, but divides, and there are two, joined, then a third, joined like the others. The mathematical drawing, and the picture of an embryo are nearly identical at this point.
     So this card becomes about growth, possibly through planning and skill, and remembering that as a pentacle this is about manifestation of money and material things.
     On the theme of threes, a fun thing: Mercedes 
Lackey Threes.  
     This is illustrative of how the numbers and their meanings begin to look if you know where to look:
Draw the circle 
Blessings