A really intelligent AI would just use a calculator.
The REPL could also come with libraries for all the important algorithms. Thus the LM could use numerical solvers and other nice toys.
Another excellent module we could augment LM's with is a search engine - already done, proven to improve the efficiency of the LM by 25x (see link). Another one would be a physics simulator.
https://deepmind.com/research/publications/2021/improving-la...
We're just starting with language models. They will improve tremendously.