This descriptive research study examined 2013 NAEP 12th-grade mathematics scores by students' use of graphing calculators in math classes and the kind of calculator students used during NAEP assessment. NAEP Data Explorer analysis included two questions from Student Factors: How often do you use these different kinds of calculators in math class? Graphing [M817601], and Kind of calculator used for test? [M830201]. The literature review included international experimental and quasi-experimental research on student use of calculators during learning and assessment. The overall (100%) M=152, SD=34 (scale-range 0-300). NAEP scores by use of graphing calculator in math class were: never use (18%) M=137, SD=29; sometimes not often use (21%) M=145, SD=34; usually use (61%) M=165, SD=32. NAEP scores by calculator use for the test: None: (35%) M=153, SD=33; NAEP provided: (39%) M=147, SD=30; Scientific non-graphing: (8%) M=146, SD=33, Graphing: (17%) M=171, SD=33. Effect sizes (Cohen, 1988) ranged from d=0.26 to d=0.90.