50 123/1 000 000 = 50.000123

Looks like a display error, right? Your query was 50+123/1000000, so the answer is correct. For some reason, the calculator is not displaying the "+".

Are you intentionally obfuscating this? If you enter it as you have displayed, (with spaces in the denominator), you don't even get the calculator: https://www.google.com/search?q=50+123%2F1+000+000 is not the same as https://www.google.com/search?q=50+123%2F1000000