If the method you have been using isn't working, consider trying something new. What a child needs is not more drills, but an intentionally different approach. We should abandon the notion that the child is broken and cannot learn; rather success is much more likely if we adjust the way we teach.
Each child differs from the next in how they learn, what their strengths are, and what they prefer as they learn. When a child is struggling, we believe in looking at the child first and uncovering the beauty of their design. Next, we believe in tailoring instruction to them.
If a person reads and does not remember what they read or doesn’t understand what they read, then they have not comprehended. They might come to believe that “reading” means correctly calling out words or correctly sounding out words. They might need to be told that words carry meaning and tell us lots of things.
Say you have two children who are struggling with reading, one in kindergarten and one in sixth grade. Logic would dictate that the further behind the child is, the longer it will take them to catch up, but in my experience, it takes about the same amount of time for children in various grades.
Our mission is to empower children to learn from a position of strength, with an approach that works in harmony with their unique wiring. Our goal specifically is to reach the children who are struggling or failing, because their natural strengths do not match their learning environment.