See inside to see the tests. You can also look at the cloud history if you are logged in: https://scratch.mit.edu/cloudmonitor/1049932922/
Results: the cloud number filter is strict (I hoped that it would allow things like 1234.56.789 or 123e45E6) When setting a value it looks like that it checks that - the value must be a string or a number - strings: must only contain digits and max. 1 dot '.', and 1 optional minus sign '-' as the first character, length must be at most 256, no hexadecimal allowed - numbers: they must be finite and the absolute value must be less than 3.163e256 (no Infinity and no NaN allowed) If the value fails the test then it is set locally but isn't sent to the cloud. The cloud only accepts 1e+100 (if converted to number by a math block) from the thumbnail. The math blocks accept more things as number than the cloud - they accept 0x41 and Infinity too. They can also return NaN - eg. (0 / 0) - but they treat it as a string. For the search indexer here is the text in the thumbnail: Which one of these is a number?