Numerology and Gematria are tools for psychic development. They are just like the Tarot in that you must interpret meanings and pick up on relationships of the variables you're working with, but numerology functions on the level of Air/Intellect (thought with form) in order to access ideas and modes of consciousness from higher levels. The tarot functions more on water/astral/subconscious levels (images) and is used to access ideas and modes of consciousness from higher levels. BOTH act as go-betweens; they go between you and the target information and work as tools to help you to train your mind to reach those higher levels through repeated usage. Once you've developed your psychic skills to a sufficient state of advancement, NEITHER is necessary. Too many people often get hung up on the use of either tool and then believe that they MUST have the tool to be effective. When that happens, the tool is no longer an educational psychic aid, but a CRUTCH. Continued dependency on tools like this after you no longer need them only hinders your further development. The next step after you've grown past the need for such learning aids is to learn to act without them spontaneously. Rituals, spells, props, and tools are not necessary for successful magick. I've known many who make use of none of those things to great effect.
How do you know when you no longer need such devices as the tarot and meditative numerology? When you start knowing the answers even before you've laid the cards out or done the number-working, then you no longer need to use those tools. In other words, if the cards and numbers are consistently only reinforcing what you already know and feel about an issue, then you don't need them.