Introduction to Number Sets

We use numbers every day, from counting objects to keeping track of quantities. Three number sets that help us do this are natural numbers, whole numbers, and integers.

Imagine you run a smoothie stand. Before opening, you count your inventory: 1 blender, 4 bags of ice, 12 bananas, and more. The numbers you use to count these supplies are called natural numbers. They start at 1 and continue as 2, 3, 4, and so on.

The stand is now open, and no customers have arrived yet. This means the number of smoothies sold is 0. When we include 0 in the natural numbers, we get whole numbers: 0, 1, 2, 3, and so on.

As the day goes on, your inventory changes. If you buy 6 more bananas, you record the change as positive 6. If you use 3 bananas to make smoothies, you record the change as negative 3. These positive and negative whole-number changes are called integers. They include whole numbers and their negative opposites.

So, these sets build on each other. We start with natural numbers, include zero to get whole numbers, and include matching negatives to get integers.