Spend less time grading with GradeMaster™ Electronic Grading Pen! Simply input the total number of questions, then mark each incorrect or correct answer by touching the pen's tip to any homework, quiz or test paper. The electronic pen counts and stores all marked answers, then calculates the percentage score at the push of a button. Grade calculation function turns on and off easily so you can write comments on student papers. Works with most standard-sized felt-tip markers, not included. Measures 6" L x 1" W and come with a guide. Requires 1 button-cell battery, included.