Numerology with the Tarot is something like using Kabbalah. It can be tricky to start using properly, but it can add more depth to your reading. It’s also entirely optional.
When I was starting out, I had three different numerology books and they all contradicted each other on basic stuff. Same as working from different Tarot books and systems. Pick ONE system and stick with it for at least six months. Most tarot readers use Pythagorean numerology (the 1-9 system) rather than Chaldean, and that’s what most modern tarot books reference.
About the 3 debate… in traditional Pythagorean numerology, it’s the number of creation and synthesis. Some readers connect that to creative expression, others to communication, because creation needs expression. Both work! The cards themselves will usually tell you which meaning fits. Three of Wands feels more like creative planning, while Three of Swords is definitely about communication gone wrong.
For the 10 questions, I reduce it to 1 for birth card calculations, but treat it as its own energy in actual readings. The Ten of Cups isn’t the same as the Ace of Cups, even though 10=1+0=1. Think of 10 as completion that contains the seed of a new beginning, while 1 is pure potential.