Instrumental understanding – having a mathematical rule and being able to apply and manipulate it. Relational understanding – having a mathematical rule, knowing how to use it AND knowing why it works.
Step-by-step explanation:
Instrumental understanding involves “memorising which problems a method works for and which not, and also learning a different method for each new class of problems” (Skemp 1987, p. 159), is a desire to know “some kind of rule for getting the answer” (p. 155) so that a student can “latch on it and ignore the rest”
