Access keeps giving syntax error

you can also use Query and create the Calculated column there:

SELECT 
    *, 
    Switch([Testscore1c1]>28,'Plus', [Testscore1c1]>15,'I',[Testscore1c1]>6,'II', [Testscore1c1]>2,5,'III',True,'IV') As Score1, 
    Switch([Testscore1cR]>28,'Plus', [Testscore1cR]>15,'I',[Testscore1cR]>6,'II', [Testscore1cR]>2,5,'III',True,'IV') As Score2  
FROM yourTableName;