The "=" symbol defines an equivalence relation. So "1+1=2" is one definition of "2", defining it as equivalent to the addition of 2 identical unit values.

2*1 also defines 2. As does any even quantity divided by half it's value. 2 is also the successor to 1 (and predecessor to 3), if you base your system on counting (or anti-counting).

The youtuber Vihart has a video that whimsically explores the idea that numbers and operations can be looked at in different ways.