9
for digits 0 to 9 0,1,3,8 have lines of symmtery
10
a nonagon
2, 4, 5, 6, 7 and 9. Also, in some fonts (such as in this one), 1, and less frequently 3.
-9
A regular nonagon with 9 sides has a rotational symmetry of 9.
I have revised this answer. This question is harder than it looks!The numbers 69, 6009 or 98886, for example, would have rotational symmetry (looks the same when rotated by 180 degrees) but not reflection symmetry.So I think the answer is going to be something like:A number which consists of the digits 6 and 9 plus or minus the digits 0 & 8 AND has the digits in the necessary order to maintain rotational symmetry.
9
It depends on how you write them. For example, 2 written here has no symmetry. Where 2 on an LCD display (eg on an elevator/lift would have rotational symmetry) Usually 0 and 8 have both horizontal and vertical symmetry.
the line which divides the number into 2 equal halves is called symmetry in numbers example:- in digits 0 to 9 the symmetry of numbers are 0, 1, 3, 8.
0 1 8
9
8
answer
for digits 0 to 9 0,1,3,8 have lines of symmtery
10