Adding property value to individual (data property)

[Sidra shah]

I have OntClass student = model.createClass(ns + "Student");
           OntClass std = model.getOntClass(ns + "Student ");
    Individual bob = user1.createIndividual(ns + name);
    Property prop= model.getProperty(ns,"marks");

I have now datatype property "marks" in my ontology. How can I assign marks
value to the individual bob?