We had a maths teacher at my boarding school who really knew his job.  He'd set the class into three.  The top four he would give them GCE O-level work to stop them getting board and disruptive.

Then there were the mainstream pupils, and then there were the real dunderheads who, through no fault of their own wouldn't pass a normal math's problem in a million years, so he set them very easy problems to stop them dreaming away for the next hour doung nothing.

I was behind in my maths, not greatly, but enough for him to notice, so our master set me slightly different problems.  Once I'd mastered the art of basic multiplication he then decided to upgrade me - longhand multiplication using decimal points.  For example

107.4432 X 2.755.  I gulped when I saw the sum, to which he smiled to himself.

"Do you know how to do it, how to carry the decimal point?"

"No, Sir."

"Well don't be nervous, Woody.  Sit down next to me and I'll show you how it's done."

He did - just three times.  After that, he knew I was on my way.

Where oh where are the teachers of the early sixties?