Is this the proper way to calculate significant years in Kabbalah?

Birth year: 1981

1+9+8+1=19 (Arcanum 19)
1+9=10 (Arcanum 10)
1+0-1 (Arcanum 1)

1981+19=2000

2+0+0+0=2 (Arcanum 2)

2000+2=2002

2+0+0+2 = 4 (Arcanum 4)

2002+4=2006

2+0+0+6 = 8 (Arcanum 8)

Etc...........

Or does one simplify completely to obtain the next increment. This leaves out any arcana that fall above 9.

I got the information from here:

http://samaelgnosis.us/kabbalah/index.htm

I just don't know if I'm doing it right. Interestingly, I did both my wives and my own using this method and it perfectly lined up with when we met. It also worked for my parents. So I think I'm doing it right but I though to myself if I simplified completely for the increments I might get a more detailed result.

Thanks and blessings.