standard_description: Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.
problem_activity: Rotate the following figure
$${90^{\circ}}$$
counterclockwise about the origin, three times.
[IMG]
A shape is formed through these rotations, with center at the origin.
Does this shape have rotational symmetry? If so, by what order/degree?
Doe this shape have reflectional symmetry? If so, what is the line of symmetry? If not, describe why not.


aligns: no