The next unit or chapter is about "rational numbers". What are rational numbers? What does the term rational numbers mean? I don't know most of these, so I read from the online textbook.
Rational numbers simply means numbers that can be written as a simple fraction. Example of a rational number is 8/4. The numbers in that fraction are the integers. Which is 8 and 4 (example). Rational numbers also means a ratio of 2 integers . One term we're all familiar with is integers, which we learned in grade 7, and grade 8. Integers are any whole number.
Irrational numbers are numbers that can't be written as a fraction. When you write it in decimal form, it goes on forever, without a pattern. An example of an irrational number is the square root of 7, or the value of pi. Both have decimals that go on forever, without a pattern. You also can't write both as a simple fraction.
Those are the major things I think we're going to learn in this chapter. Feel free to comment or add on to what I missed. :)