Engagement entails much more than rote repetition of a procedure. Math worksheets tend to present very similar problem types over and over, leading to mundane practice of disassociated skills. For students who understand the material and successfully complete an assignment, another worksheet becomes meaningless. On the other hand, for the students who don't understand the material, an alternative method of instruction is what's needed. Another worksheet simply adds to the student's frustration, or worse, contributes to a belief that "I'll never understand math." A cute image or a "fill_in_the_blanks" riddle does nothing to increase engagement or learning (and let's face it, those riddles are not funny!). Instead, teachers need to increase engagement by providing students with exercises in which they discover patterns and relationships, solve problems, or think creatively about math relationships.
Have you ever noticed how many K┨ math content websites are devoted to math worksheets? There seems to be an increase in websites that cater to desperate teachers and parents by offering fast, free "worksheet generation", free fractions worksheets," etc. Now, as a former teacher I am not saying that one should never use math worksheets; however, I do believe that many teachers are using a very superficial method of instruction that relies too much on low_level math worksheets and hands_off instructional approaches. Worksheet lessons move from reading the directions aloud, to doing sample problems as a group, to completing the worksheet independently (or at home with parents), day in and day out. Teaching needs to be more than passing out worksheets. Whether you are the classroom teacher, instructional specialist, or parent, the methods you use greatly impact the level of understanding achieved by your students.