I am creating a simple spreadsheet for primary school kids that will correct certain activities that they do. I want them to fill in the missing numbers in a sequence, e.g. 2, 4, 6,?, 10. How do I program Excel to give feed back to the children if they are correct or incorrect. Is it done through conditional formatting? If possible I would like each answer to be ticked or marked wrong with some degree of feedback like 'Well Done, that is correct.'