After like 1-2 hours, I've finally done it. This is ValueNum, a project that was used to expand Scratch's limits of numbers from 2^1024 all the way to 10^200000 (i think). It's complicated but basically, the numbers you choose are both put into 2 separate lists. When both lists are 'lined up' (just a way to avoid mistakes like 23+230 doesn't equal 460), each place value is added (and possibly regrouped) to form a new number. It uses place value to create large numbers (which is also why it's called valuenum) and scientific notation to represent them. Look inside the project for blocks. (there's only 2, and both of them are related to adding, i will make more in the future)
Inspired by BigNum and EternityNum All code was made by me. Aside from that, please do not use this, use BigNum, Although this is 'probably' more specific, BigNum is more practical for big numbers and stuff, and it's faster. Also I currently don't know how to even get BigNum to work on your projects... Anyways, thanks for reading :D