She cannot share 668 cookies so that she and her friends have an equal share of whole cookies, because 668 isn't exactly divisible by 8. 668/8=83 and 4 cookies over. Lainey would need to cut or break each of the remaining 4 cookies in half so that she and her friends take half a cookie each making each one's share 83 and a half cookies. She could also remove 4 cookies before sharing them out, so Lainey has 87 cookies and her friends have 83: 7*83+87=668.