Recent research findings have shown a positive relationship between achievement and the amount of time students engage in learning activities. Since the greatest percentage of class time is allocated to seatwork, with worksheets being the most frequently used activity, a study investigated the effects of using three types of worksheet tasks on engaged learning time (ELT) for fifth grade students of three levels of reading ability (high, middle, low). The 134 subjects were assigned to one of three treatment groups: (1) drill, consisting of worksheets composed of multiple choice, true/false, and fill-in-the-blank questions; (2) comprehension, consisting of worksheets designed to promote comprehension of subordinate lesson concepts by requiring analysis, evaluation, or application of the lesson material; and (3) structuring, consisting of worksheets requiring students to locate and write main ideas appearing in the text. The results indicated that low level readers in the drill treatment spent a significantly greater amount of their time on-task than did high level readers in the same treatment. In addition, high and middle level readers assigned to the structuring treatment had a significantly higher engagement rate than did high level readers in the drill treatment. Finally, subjects at each of the three reading levels in the comprehension treatment spent significantly more time on-task than did high level readers in the drill treatment. (FL)