Math Problems for 9th Graders: Help for Struggling Students

Help With 9th Grade Math

If you're struggling with 9th grade math, it's most likely because you haven't yet mastered some of the fundamental concepts that are essential to success. You may find it helpful to brush up on the skills described below.

Simplifying Expressions

This skill may also be referred to as 'evaluating' an expression. An expression states that certain operations need to be performed. For instance, the expression 20 ÷ 4 tells us that 20 needs to be divided by four. When those operations are completed, the expression is considered simplified. Examples of operations that you might need to perform include evaluating an exponent or a radical, applying the distributive property or dividing.

To simplify an expression properly, you'll need to follow the order of operations, which is often represented by the acronym 'PEMDAS.' Use this acronym to remind you of the steps to follow. For instance, you do the operations in the parentheses first, and then you simplify any exponents. Next, you perform any multiplication or division from left to right, followed by any addition or subtraction from left to right. Here's a sample problem:

4^2 + (6 - 2) ÷ 4

= 4^2 + (4) ÷ 4

= 16 + 4 ÷ 4

= 16 + 1

= 17

Solving Equations

You'll spend a lot of time solving equations in 9th grade math. The key rule to remember is that the quantities on both sides of an equation are assumed to be equal. To keep them equal, and thus get the right solution, you must always perform the same operation on both sides of the equation. Here's an example:

5(x + 2) = 30

5x + 10 = 30

5x + 10 - 10 = 30 - 10

5x = 20

5x/5 = 20/5

x = 4

Evaluating Functions

You'll probably be introduced to functions in 9th grade. A function shows the relationship between two variables. It allows you to find the value of one variable for any value of another variable. Although it looks complicated, it's really just a fancy way to say, 'Plug a number in for x and simplify.'

For instance, imagine you're given this problem:

Given f(x) = x^2 + 2x + 4, find f(-1).

This is the same thing as saying, 'Evaluate x^2 + 2x + 4 if x = -1.' In either case, you just plug the value of x into the equation, like this:

f(x) = x^2 + 2x + 4

f(-1) = (-1)^2 + 2(-1) + 4

f(-1) = 1 + (-2) + 4

f(-1) = 3