To represent the expression of starting at -6 and moving up 3 units, you can use the following subtraction (or addition) expression:
Starting value: \(-6\)
Movement: \(+3\)
In mathematical terms, this can be expressed as:
\[ -6 + 3 \]
Calculating this gives:
\[ -6 + 3 = -3 \]
So the resulting value after moving up 3 units from -6 is \(-3\).