I am not a devoted practioner of numerology. On the surface it seems really simple because the value of numbers doesn't change. As long as your math is correct there shouldn't be any problem.
But of course, nothing is ever simple.
The first problem I had with numerology was the order in which to add. I used to add up letters. A is 1, B is 2. But what happens when you get to double digits? The 10th letter is J. Most people start reducing back to single digits so J becomes 1 and that's fine if you're working with one word. But in an entire sentence things get a bit tricky. I would add up all the letters in each word, then add those numbers. Adding the value of all the letters then reducing that sum to single digits gives a completely different number.
Some people think vowels should be omitted because they represent personalities and emotions. If the numerology spell only involves the person casting, using the sum of consonants makes sense. If the spell involves other people then emotions might be a good thing to take into consideration.
I think it's wise to look at all the numbers to see if something occurs repeatedly. There's 7 letters in my first name, 7 letters in my maiden name, 7 letters in both my husband's first and middle names. I was born 1-7-77 at 1:27pm. If I add all that up I don't get 7.
I tend to think of numerology like astrology. The sun signs tells a lot. It's a good general indicator. But it doesn't tell the entire story. The moon sign tells us more, and the rising signs tells us a little more. But we never get the whole story because no matter what astrologers may wish, there is no birth chart that will tell exactly what will happen or how one person will feel, how they will act, or how they will be affected.
You can find numbers everywhere in everything. You can focus on the time, the date, the value of letters, the address, or how many people were present. You can count from when it happened or when you first learned of the event. And you can waste a lot of time looking for meanings when you should be doing something.
I do magick every day. But I don't do it all day and I don't do the same kind of magick each day. Numerology is a great tool. Just remember there are other tools, too.