Is it normal i can add seriously quickly/math ability?

Hi guys, I have this thing that I am able to do, it’s like an ability I have to quickly add up numbers, quite often happens unwillingly.

I’ll give some examples, like let’s say I’m watching the news and the weather report comes on and they have the 8 day forecast displayed on screen, I can quickly add the numbers up for the week almost instantly, another time I call upon this “ability” is when I perform my cash count at work, for whatever reason I can count the coins and notes and then times them by the monetary value once again practically instantly.

The third example and this is when I feel things can get really unusual or freaky is when I am driving and I come across road signs or varying speed limits, my mind just clicks into this mode and I start unwillingly performing the addition, like I can even do it with multiple words on road signs, my mind for whatever reason converts the words into the amount of letters per word and I just start adding them up as if they were numbers.

example:
California + 14 + miles
Ohio + 18 + miles
Kentucky + 88 + miles
Alaska + 126 + miles = 294

The following adds up to 294 if the addition signs were placed as shown above, I’m curious to seek answers as to why I do this practically unwillingly, so basically my question is, does anyone out there do the same thing? Or does anyone know of anyone who can do the same thing? or had anyone heard of such a thing at all anywhere? If you guys could please attempt to help and spare some time, it would be greatly appreciated. Thanks