These stamps from Classroom SAFE-T are easy to grasp and use, and they stamp helpful math charts that teachers and students will appreciate. Each rubber stamp measures 3” x 3” and holds a different graphing chart. The X-Y Axis Stamp is a 144 block grid with an x and y axis and is available separately or in a set with the other two. The 100 Grid Stamp can be used as a 100 block grid, a 1-100 chart, or a multiplication chart. The Polar Coordinate Stamp has concentric circles at .25” radius increments and main radii at 15 degree intervals subdivided at 5 degree intervals. None of the stamps include numbers, so the teacher or student can fill these in according to their purposes. Inkpads not included.