The data I received from my learners out of their PAT maths test shows me that many of my learners who are working below the national standard have a noticeable gap between their knowledge, and their strategies. It also confirms for me what I have been seeing in group work, where their lack of knowledge is holding back the acquisition of new strategies, or using them successfully. So I continue to hypothesise that my learners are not acquiring or retaining maths knowledge.
Here are the test results from one of the Year 6 boys in my class, you can quite clearly see his gaps in Number knowledge. You can also see that he is capable of achieving higher level Strategy questions, which makes me think he could achieve more of these questions if his knowledge was keeping up.