 Hello, kids! Let's talk about sets. A set is a group of things. Here are some examples. A set of envelopes. A set of rulers. A set of paper clips. A set of pencils. A set of books. How about this? It has nothing in it. You call this an empty set. Now let's talk about equal sets. You can say that sets are equal when you see that set A and set B have the same objects and the same number of objects. So you can say that 2 ice creams is equal to 2 ice creams. Now if set A and set B have the same objects but different in number, these sets are not equal. You can say that 2 ice creams is not equal to 3 ice creams. Now what are equivalent sets? If set A and set B have different objects but have the same number of objects, we say that they are equivalent sets. But if set A and set B have different objects and have different number of objects, we say that they are not equivalent. Some sets have more and some sets have less. We can use less than and greater than symbols to compare them. If set A has more objects than set B, we say that set A is greater than set B. If set A has less objects compared to set B, we say that set A is less than set B. That's all for today kids and I hope you understood what sets are and how to compare them. It's time to answer your book. Good luck!