Natural numbers are numbers that appear as a result of counting. The numbers one, two, three, four and so on are natural. Negative and fractional numbers do not belong to natural numbers. Zero, most often, is not considered to be natural.

Content:
- Natural numbers - definition and designation
- Operations on natural numbers
- Classes and ranks
- Comparison of natural numbers
- Addition of natural numbers. Column Addition
- Addition in a column
- Subtraction of natural numbers
- Subtraction in a column