I will admit that there is one type of worksheet that I used in the past and found relatively beneficial, although it had a different kind of flaw. For my Basic Math, Pre_Algebra, and Algebra classes, I had several books of "self_checking" worksheets. These worksheets had puns or puzzle questions at the top, and as the students worked the problems they were given some kind of code for choosing a letter to match that answer. If they worked the problems correctly, the letters eventually answered the pun or riddle. Students enjoyed these worksheets, but there are a couple problem areas even with these worksheets. Some students would get the answer to the riddle early and then work backward from letter to problem answer, so they weren't learning or practicing anything.
Your aim should be to make math fun for your child and help them gain a solid understanding of the basics. Encourage your child to incorporate math into their daily activities, help them do mathematics worksheets, and then use the lessons therein to create fun activities for your child. The secret to learning math is to have an open mind about it. Just because you hated math doesn't mean your child should, and you will be doing them a disservice if you pass your negative feelings on to them. Make learning math fun, get a comprehensive set of mathematics worksheets to make it exciting and stimulating, and encourage your child's efforts all the way. Every math genius had to start with 1 + 1, just like your child.