Is mathematics empty? Buddhists say that everything is empty.

Is mathematics empty?

I thought that "empty" meant conceptually constructed. But how can the fact (not the expression) 2 + 3 = 5 not be a fact which is true regardless of how we are counting?
Emptiness in eastern philosophies usually have a more subtle meaning than we use in the west. Check this wikipedia article on Emptiness. And there are many answers regarding emptiness (sunyata) like this one. There is also an article in wikipedia on Śūnyatā.

The most common understanding on emptiness (on Buddhism) is that it is dependently originated. It means that it does not have inherent meaning or value, but it relies on other things. In mathematics the numbers two, three, five and so on just has meaning because of the number one. And also, the number one only has meaning relying on the other numbers.

In a more practical sense, numbers only has meaning because of the objects, like apples, rocks or sheep. Now, emotions, that have no clear bounds, can't be numerically described. You could say that you felt happy twice today, but you can't express its intensity and form numerically. Then math is true not because it has inherent meaning, but because it works for what it is used.

There is another interpretation I read on this QA (and also in some wikipedia article but I couldn't find it):


  [Emptiness is] a flashy way of reminding us that we only define things in relation to what they are not. 


In math words, the number one only exist because there is the zero. And there is zero only because of the one. (Although the zero was "created" much after the integer numbers). If we couldn't distinguish between zero and one, no numbers would make sense. There is only happy because there is not-happy. There is only "self" because we define our bounds, we define what is not-me.

Likewise we can only perceive suffering if we know what is not-suffering.

So, when we say that math is empty, we don't mean that it is false or is meaningless. But we mean that is not absolutely true, that it is true in relation to something. Truth is a relation, not an absolute thing.