just do a console.log('inputs', a, b) inside the add function – you will know right away if your answer matches the expectation. there are no tricky/deceptive tests in this kata.

I wondered about that! OK, I'll give it a try :-)

The same way they teach to at primary school, digit by digit.

It's about time that I learn how to deal with big integers in Javascript. Can anybody point me in the right direction for learning the best way?

I'm not asking anyone to solve this for me, just point me in the right general direction for learning how to deal with very large numbers in Javascript.

Test cases are not clear - I'm not sure why my solution is failing.