I went through this exact issue with a junior employee moved to my team to do some analysis that required a basic understanding of medians/means and a little intro stats.
It took about 8 weeks of tasks with incremental mathematical challenges to overcome this, and at least reach the point where he could do his work, and apply the fundamentals learned to solving more complex problems.
In the end he "could do math", the real issue was he had never "put any work into math".
It took about 8 weeks of tasks with incremental mathematical challenges to overcome this, and at least reach the point where he could do his work, and apply the fundamentals learned to solving more complex problems.
In the end he "could do math", the real issue was he had never "put any work into math".