3 ms·

But children have to be separated by age to compare and rate their progress, in order to separate them further.

• eru 11y ago
  Are you being sarcastic?
  • conceit 11y ago
    Yes, but on another note, age-group is a murky term to deal with, because a delta t of one year is a lot of time, when development is still very fast as is obvious in weight and size gains.