Column Styling Rules Invalid Operator Error

[mifosses]

I have a report table that has 10 rows of data to style. 

For reference, I am using the Dynamic or Unknown Fields workaround to apply column rules to multiple columns as outlined here 

For 3 of these, I have a Column Rule formula that styles it when the value is less than 89:

[Core Product] IN ("AS", "MS", "VOM") AND [_CurrentField_] < 89

This works as intended.

For the other 7, I thought I could use a similar formula but when the value is less than 80:

[Core Product] NOT IN ("AS", "MS", "VOM") AND [_CurrentField_] < 80

However, this results in a Parse Error: Invalid type in operator <

Not quite sure where this is going wrong, any help is appreciated. 

[binuacs]

@mifosses make sure the [_currentField_] are numeric 

[mifosses]

Thanks, they are numeric. Not understanding why it would not impact the IN statement but does on the NOT ON statement

[binuacs]

@mifosses try the below formula, it is working for me

[Core Product]  NOT IN ("AS", "MS", "VOM") AND toNumber([_CurrentField_]) < 80