Depending on your own Mathematical background, you may have learnt to place commas between the thousands, millions etc. Eg. 2,300 or 1,200,300.
This is currently not the convention for teaching how to write numbers in Australia. Here we usually write numbers with a slight gap or space between them. Like this 2 300 or 1 200 300.
In Mathspace however you don't even need to put a space, we will automatically space the numbers for you!
One digital reason why commas are not used as place value separators is that a comma is most commonly used to seperate numbers in a list, so if you enter a comma in the number 2,300 -> Mathspace will think you mean two numbers, the number 2 and the number 300.
This article from Australian Mathematical Sciences Institute on 'Using place value to write numbers' has some more interesting information on commas and place value, you might find it interesting.