manipulative

Etymology

manipulate + -ive

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. 2012-01, Robert M. Pringle, “How to Be Manipulative”, in American Scientist, volume 100, number 1, archived from the original on 2013-10-03, page 31
2. Tending to manipulate.
3. (derogatory) Reaching one's goals at the expense of other people by using them.
   You manipulative bitch!

noun

1. (mathematics) 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. April 25, 2008, Kenneth Chang, “Study Suggests Math Teachers Scrap Balls and Slices”, in New York Times