Eighth-grade students connect their understanding of rates and relationships to points on a line, using linear equations and functions to analyze and solve problems. They also learn about the Pythagorean Theorem. Here are a few examples of what your child will study throughout the year, questions to ask his or her teachers and tips for reinforcing math skills at home.

### Number System

- Understand the difference between rational and irrational numbers; for example, rational numbers can be expressed as fractions and decimals, but irrational numbers can only be written as an unending decimal.
Pi: (π = 3.14159265359…) is an irrational number because it is an unending decimal. A number such as 1.5 is rational because it can be written as a fraction:

### Expressions and Equations

- Work problems that involve radical numbers, including square roots and cube roots.
2 + 2(√7)
^{2}

= 2 + 2(7)

= 2 + 14

= 16 - Write and solve linear equations.
5
*x*+ 3*x*= 8

8*x*= 8

*x*= 1 - Solve basic equations that use exponents.

### Functions

- Comprehend functions as rules that assign one input to one output and that can be expressed using tables, graphs and equations.
X 0 1 2 2 3 4 Y 1 2 1 3 0 5 This is not a function because “2” is an X value more than once.

- Complete word problems that involve proportional relationships; be able to illustrate the solution using a graph.

### Geometry

- Understand the Pythagorean Theorem and how it is used as an equation to solve problems.
Q:

A:*a*^{2}+*b*^{2}=*c*^{2}

*a*^{2}+ 4^{2}= 5^{2}

*a*^{2}+ 16 = 25

*a*^{2}= 9

*a*= √9

*a*= 3 - Gain knowledge of the difference between congruent and similar two-dimensional objects.
Q:

A: These two triangles are similar triangles because the second triangle increases by a factor of 2.

(6 × 2 = 12); (2 × 2 = 4)

### Statistics and Probability

- Learn and use the best-fit line method to compare two values.

- "Parents’ Guide to Student Success: 8th Grade," National PTA
- "Parent Roadmap: Supporting Your Child in Grade Eight Mathematics," Council of the Great City Schools
- "Parent Toolkit: Middle School Guides," ParentToolkit.com
- Patti Ghezzi, "8th Grade Academics: What To Expect," SchoolFamily.com