### Integers (0-2)

In this chapter, we expand our number system from whole numbers to the integers. This expansion includes negative numbers, and we can now solve open sentences like X + 7 = 2 which could not be solved precisely using whole numbers.

### Sets, Subsets, and Operations with Sets (0-3)

Sets, Subsets, and Operations with Sets (0-3) is the third chapter of Book 0, Intuitive Background, in the Elements of Mathematics Curriculum. It presents the language and notation used in the study of sets and objects. The set operations intersection, union, difference, and complement will be studied. Set diagrams and set examples drawn from previous chapters will be used to enhance the concepts.

### Ordered N-tuples (0-4)

We explore ordered pairs and triples, and take our first look at open sentences in more than one variable.

### Mappings (0-5)

In this course we investigate the idea of mapping of function, a concept central to almost every branch of mathematics. In the second half we investigate stretcher and shrinker mappings which will lead us to the development of rational numbers and the expansion of our current set of numbers.

### Rational Numbers (0-6)

In this chapter we expand our number system from the integers to the rational numbers. The new numbers are based on our work with stretcher and shrinker mappings in 0-5. We will now be able to solve equations such as 3x = 5.

### Decimals (0-7)

In this chapter we study the decimals as a subset of the rational numbers.