manipulative

adj

1. Using manipulation purposefully.

   “As in much of biology, the most satisfying truths in ecology derive from manipulative experimentation. Tinker with nature and quantify how it responds.”

2. Tending to manipulate.
3. (derogatory)Reaching one's goals at the expense of other people by using them.

   “You manipulative bitch!”

noun

1. A manipulable object designed to demonstrate a mathematical concept.

   “Some children need manipulatives to learn math basics, Dr. Clements said, but only as a starting point.”