Another problem with almost all worksheets is that they don't prevent incorrect answers. Self_checking worksheets just let the student know they did something wrong__after the fact. I am a firm believer in the concept that, if at all possible, learning should be structured in small chunks in such a way that there is very little possibility for error. Worksheets often allow for mistakes to be made and then to be repeated many times. A mistake that gets practiced is extremely difficult to correct. This especially happens when worksheets are used as time fillers or baby sitters and the work isn't really being supervised.
Math worksheets don't provide immediate feedback _ Most teachers are familiar with the long delay between when students complete a worksheet, and when they get their correct page. Most don't get anything back until the next day or the next week. In the meantime, the students continue to practice incorrectly. It's no surprise that immediate feedback has been shown to increase student performance and diligence. Unfortunately, math worksheets have no mechanism for keeping a student from moving to the next problem until after they demonstrate understanding. Good curriculum software can address this issue by giving students instant responses and strategic feedback. The use of visual cues and auditory feedback helps students quickly recognize their fraction errors and self_correct. This just_in_time feedback system eliminates practicing incorrectly, while promoting self_correction and independence.