Fill in the blanks. Then, choose the property of addition you used.
[] + 9 = 9 + 6
[] + 0 = 6
6 + (7+2) = (6+7) + []
![Fill in the blanks Then choose the property of addition you used 9 9 6 0 6 6 72 67 class=](https://us-static.z-dn.net/files/d2f/3d62c39f903f0f294a28320ca47e8e8a.png)