I have a problem where it is often very difficult for me to solve simple math problems without thinking about them visually, but at the same time, I have poor spatial reasoning and so I'm unable to keep clear diagrams in my head for long. Therefore, this combination makes solving simple problems take much longer than needed. It may be due to the fact that since I was young, I always thought thinking visually (whenever it's possible) is the "most comprehensive" way to understand a problem, and so I've trained my brain to always think visually, even if it makes me very inefficient.
I'd like to know how to train my brain to not think visually anymore when it's not needed, particularly for simple problems that do not need to be thought about visually.
Here's an example:
Bob and Jake both started off their schooling by going to kindergarten. The cutoff for entering kindergarten in their area is that you had to be 2 years old by September of that year (otherwise you would have to wait till the next year to join).
By years (ignoring the month they were born and just looking at their birth year), Bob is 4 years older than Jake. But Bob was born in October, and Jake was born in June. How many grade levels apart are they (assuming once they entered kindergarten, they didn't skip or fail any grades)?
The way I would think about this is by drawing out a picture in my head like below and reasoning based on the picture (even though it's time consuming and difficult to do):
However, coming up with the right picture in my head and then reasoning visually takes a while (like 5-7 minutes).
I asked my friend about this, and he just thinks this way:
Normally Bob would be 4 grades ahead of Jake. But since Bob missed the cutoff and had to wait another grade, he's now only 3 grades ahead of Jake.
That's a much simpler thought process that took my friend substantially less time, but even to try to understand that statement, I tend to draw out this type of picture in my head, but then I get stuck with a question:
From some type of vague sense of logic, I could guess that since Bob missed the cutoff, he'd be one grade level less than he would normally be. But I'd have a good chance of getting this wrong and it's very difficult to make this make sense to me, unless I go back to thinking about their birth years on a timeline as in Picture One, because that makes it crystal clear that Bob "loses" a grade level and that their grade level difference shrinks by one.
My question is: how can I ditch the need to think as in Picture One/Picture Two, and just think verbally/logically like my friend did, so that I can speed up my thought process?