BackPrealgebra Study Guide: Integers, Order of Operations, and Rational Numbers
Study Guide - Smart Notes
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Chapter 1: Integers & Expressions
Absolute Value
The absolute value of a number is its distance from zero on the number line, regardless of direction. Absolute value is always non-negative.
Notation:
Example:
Adding & Subtracting Integers
Same Signs: Add the absolute values and keep the common sign. Example:
Different Signs: Subtract the smaller absolute value from the larger, and keep the sign of the number with the larger absolute value. Example:
Subtraction Rule: Subtracting a number is the same as adding its opposite.
Formula:
Example:
Multiplying & Dividing Integers
Same Signs: The product or quotient is positive.
Example:
Different Signs: The product or quotient is negative.
Example:
Order of Operations (PEMDAS)
To evaluate expressions correctly, follow the order of operations:
Parentheses / Grouping
Exponents
Multiplication & Division (left to right)
Addition & Subtraction (left to right)
Example: Evaluate Step 1: Exponents: (if the negative is outside the exponent, ) Step 2: Multiplication/Division: , Step 3: Addition/Subtraction:
Chapter 4: Rational Numbers & Fractions
Rational Numbers
A rational number is any number that can be written as a fraction , where and are integers and .
Examples: , , (since )
Simplifying Fractions
To simplify a fraction, divide both the numerator and denominator by their Greatest Common Factor (GCF).
Example: Simplify GCF of 8 and 12 is 4.
Multiplying Fractions
Multiply the numerators together and the denominators together:
Formula:
Example:
Dividing Fractions
To divide by a fraction, multiply by its reciprocal ("Keep, Change, Flip"):
Formula:
Example:
Adding & Subtracting Fractions
Fractions must have a Least Common Denominator (LCD) to be added or subtracted:
Formula:
Example:
Practice Test
Section A: Integers & Order of Operations
Evaluate:
Calculate:
Evaluate:
Section B: Rational Numbers & Fractions
Simplify to lowest terms:
Multiply:
Divide:
Solve:
Additional info: The above practice problems reinforce the core concepts of integer operations, order of operations, and fraction arithmetic. Students should show all steps and simplify answers where possible.