Greatest element and least element

Imagine you have a big box of toys. You love all your toys, but some are your favorites and some you don't like so much. The greatest element is like your favorite toy - it's the one you love the most and is bigger or better than all the other toys in the box. The least element is like the toy you like the least - it's the smallest or least important toy in the box.

Now think about numbers instead of toys. The greatest element of a set of numbers is the biggest number in the set. For example, if you have the set {1, 2, 7, 9}, the greatest element is 9, because it's the biggest number in the set. The least element is the smallest number in the set. In the same set of numbers, the least element is 1, because it's the smallest number in the set.

So, the greatest element is like the king or queen of the numbers in the set, and the least element is like the follower or smallest one in the group. Just like your favorite toy and the toy you don't really like, each number has its own importance in the set.