Because you can’t hold two numbers in your mind simultaneously, or imagine one adding to another and the result of that. It’s probably difficult to explain if you are able to visualise things.
I can do maths on paper when I can see it on front of me. But I don’t have a mind’s eye.
Yeah I can’t hold the numbers in my mind. It’s like i can grasp the concept of a number for a split second and then it’s gone like smoke. How do you add two numbers together in your mind? Like, what happens?