Manipulatives are images that students can move around.
If your students are not able to move manipulatives on an assignment, make sure that the Add Manipulative icon appears on the images in Edit assignment mode.
If they are inserted as regular images, students will NOT be able to move them.
If manipulatives, answer boxes, or fill-in-the-blanks do not show up for students, click and drag these elements back and forth on the canvas in Edit assignment mode. This should help sync the boxes so that they will then appear on the students' view.
If you still need assistance, please submit a request.