Anatomy of a mathematical expression

 

The type of the operator or operand.

 

The name of the operand in the context of its operator.  In this example, the first operand of a Multiply operator is known as the multiplicand.

 

A description of the associated node.  In the case of operators, the description is based on the descriptions of its operands.  The presence of a question mark indicates that an operator placeholder has yet to be filled.  In such instances the expression is deemed to be incomplete.

 

The selected node is the target of Calculation Builder operations.

 

Some operands – specifically the Parameter and the Literal – require you to enter a value.  The Parameter needs a name (in this example a Parameter has been assigned the name r, perhaps to represent the radius of a circle) and the Literal requires a numeric value.  To specify a value for such operands, select the node.  This will display a value editor: use this to change the operand value.

 

A placeholder is an operand that has yet to be selected.  It is denoted by the words "awaiting selection".