Your math skills may be rusty, so this page will review common terms you'll see when learning about algebra concepts.
Natural numbers - whole numbers used for counting things (i.e., 1, 2, 3, 4, 5)
Integers - natural numbers that include negative numbers
Real numbers - any number using whole or partial values (i.e., 1.31, 12/143, 0.000341)
Positive numbers - real numbers with values greater than zero. Positive numbers can be denoted using a plus sign (+). Numbers are also assumed to be positive if they lack a sign at all. +9 and 9 would both be considered positive numbers.
Negative numbers - real numbers with values less than zero. Negative numbers are denoted using a minus sign (-).
Absolute value - the numerical part of an integer. Absolute value is notated as |n|, where n represents a number (i.e., |3| = 3, |-8| = 8)
Number Line
A number line is a way of representing number sequencing. It is made up of segments of equal length that aid in adding and subtracting values. Number lines often have 0 in the middle, but can really be used with any range of values.
By plotting values on a number line, we can also compare values to make comparisons. Since numbers on the left side of the number line are smaller than numbers on the right side of the number line, plotting points can help when sequencing least to greatest. Number lines can also be used to compare values written in different forms, like fractions and decimals.
Mathematical Operations
Let's review the basic operations in math and terms commonly associated with these operations.
Addition (+): In addition, we are simply adding two numbers together. The numbers being added are called addends. The resulting answer is called the sum.
Subtraction (-): During subtraction, we are removing one number from another number. The answer to a subtraction problem is called the difference.
Multiplication (x): Multiplication is like repeated addition. Like saying you're adding 2 to itself 5 times: 2 x 5. The numbers being multiplied are called factors, and the final answer is called the product.
Note: any number multiplied by 1 remains the same: 238 x 1 = 238
Note: any number multiplied by 0 is 0: 238 x 0 = 0
Division (
Note: any number divided by 1 remains the same: 26
Note: any number divided by itself becomes 1 = 3
Mathematical Operations
Let's review what these operations look like when working with negative numbers. Remember, negative values move left on the number line, while positive numbers move right on the number line.
Addition (+): When adding two negative numbers, the sum will become more negative. A simple way of conceptualizing this is to think about adding the numbers without the negative sign and then tacking the sign back on at the end.
When adding a positive number and a negative number, the final answer will take on the sign of the larger number.
and 
and 
Adding a negative number is the same thing as subtracting a positive number. We could rethink 7+-3 as 7-3 and still get to the correct answer.
Subtraction (-): During subtraction, we are removing one number from another number. The answer to a subtraction problem is called the difference.
Multiplication (x): Multiplication is like repeated addition. Like saying you're adding 2 to itself 5 times: 2 x 5. The numbers being multiplied are called factors, and the final answer is called the product.
Note: any number multiplied by 1 remains the same: 238 x 1 = 238
Note: any number multiplied by 0 is 0: 238 x 0 = 0
Division (
Note: any number divided by 1 remains the same: 26
Note: any number divided by itself becomes 1 = 3
