# Information That Should be in an 8th Grade Math Chart

A mathematics chart for 8th grade students should provide fundamental math rules and steps needed to solve linear equations and geometrical functions. By this time, an eighth grader should have mastered the following mathematical concepts:

- Adding, subtracting, multiplying and dividing decimals, fractions and whole numbers
- Turning a decimal into a percentage and vice versa
- What a negative number is and how to add, subtract, multiply and divide them
- Solving simple word problems involving liquids, solids and distance
- Geometrical equations (area of a circle, area of a rectangle, etc)
- Cubing and squaring of whole numbers

Helpful information to include on math chart for 8th grade students needs to prompt the student rather than supply the student with too much information.

Although each U.S. state has slightly different educational requirements concerning what instructors need to teach public school students, an 8th grade math chart should offer the following information:

## Rules of exponents

Examples:

- 4
^{2}= 4 x 4 = 16 - 4
^{2}x 4^{2}= 16 x 16 = 256 - 5
^{2}+ 5^{2}= 25 + 25 = 50 - (-1)
^{3 }= -1 (odd exponents will result with a negative answer; even exponents with an even answer)

Other useful exponential concepts to put on the chart include exponents with fractional and decimal bases; power rule; relationship between square roots and squares and simplifying exponential expressions.

## Algebraic concepts

How to solve linear equations involving one variable.

Examples:

- x + 4 = 12
- x + 4 – 4 = 12 – 4
- x + 0 = 3
- x = 3

- 4x – 12 = 0
- 4x – 12 + 12 = 0 + 12
- 4x = 12
- x = 3

Other algebraic information relevant to 8th grade math includes representing a linear function on a simple graph; solving linear equations involving multiplication or division; determining the y intercept and slope of a linear function on a graph and using linear functions to solve multi-step word problems.

A good simple word problem to practice using linear equations is:

*70 less than 4 times a number is equal to the number. Find the number.*

The equation for this statement would be written 4 times an unknown number x minus (less than) 70. Numerically, the equation would be written this way: 4x – 70 = x

- 4x – 70 + 70 = x + 70
- 4x =70
- x = 17.5

## Geometrical and measurement concepts

Math chart information useful to 8th graders should include:

- Using the Pythagorean Theorem
- Finding distance between points on a coordinate plane
- Converting basic U.S. measurements into metric measurements
- Multiplying and dividing pints, quarts and gallons
- Multiplying and dividing feet and inches
- How to find perimeters, volumes, surface areas and circumferences of various geometrical shapes
- Finding the third angle of a triangle and the fourth angle of a quadrilateral

## Introduction to statistics

Provide examples showing how to find statistical means, medians and ranges

Provide examples showing how simple probability works, such as what is the chance that a die will land on any number one through six? Because six possible ways exist for the die to land on one of these numbers, the equation would be 6/6 and the answer would be 1. Remind students on the chart that all probabilities are either “0” or “1”, which is then converted to a percentage.

Other useful statistical information to place on a mathematics chart for 8th grade students include types of graphs (box, line, scatter, etc.); what a Venn diagram is and solving problems with permutations and combinations.

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