If all GPT-4 is doing is searching the internet and compiling the results, then how come I can ask it to add two 6 digits numbers that appear nowhere on the int

If all GPT-4 is doing is searching the internet and compiling the results, then how come I can ask it to add two 6 digits numbers that appear nowhere on the internet and it will get it right? Sure, it's not exactly amazing that a computer can add numbers but it does show that it is doing more than pattern matching.