Or looking at it from a different angle - before INSETT days the school year was 190 days long - so children were in school for 190 days.
Now with INSETT days the school year is 195 days long, with 5 of them being INSETT days.
So children are still in school for EXACTLY THE SAME NUMBER OF DAYS AS BEFORE.
No loss of education, no extra days childcare for parents to find
(I'm not a teacher, I just worked that out from previous posts. Can one of you good people please check my working out?)