0 + 9 = 9
1 + 8 = 9
2 + 7 = 9
3 + 6 = 9
You can also, of course, use fractions and negative numbers.
It is an irregular 8 sided octagon
9
9 x 9 = 81 :(
The numbers are: 9+sq rt of 11 and 9-sq rt of 11
9
9409
9 and 6
3
1 divided by 9
They are 25 minus 16 = 9
3 multiplied by itself (3x3) makes 9.
499 + 49