So here is another post I keep for my own reference, since I keep forgetting about precision and scale, primarily which is which.
The Oracle Concepts guide states that the NUMBER datatype stores fixed and floating-point numbers. A column with the NUMBER datatype can be defined as follows:
column_name NUMBER (precision, scale)
The precision defines the total number of digits.
The scale defines the number of digits to the right of the decimal point.
If you specify a negative scale, Oracle Database rounds the actual data to the specified number of places to the left of the decimal point. For example, specifying (7,-2) means Oracle Database rounds to the nearest hundredths (source).