Prealgebra 2e PDF Download – OpenStax (2nd Edition, Foundation Math)

Prealgebra 2e, published free by OpenStax, is the book to open before any university-level math course if arithmetic, fractions, decimals, or basic equations feel rusty. It covers whole numbers, integers, fractions, decimals, percents, the properties of real numbers, and solving linear equations — the Foundation-level math skills that entry tests and first-semester quantitative courses assume every student already has.

Students preparing for a university entry test, or starting a Foundation/bridging-year math course before their BS program begins, get the most from this book. Each chapter rebuilds a skill from first principles and then applies it, so a student can start at Chapter 1 with plain arithmetic and end at Chapter 11 graphing linear equations — genuine revision, not a shortcut, and exactly the kind of step-by-step practice a placement or entry test rewards.

Book Overview

Chapter List

Chapter 1: Whole Numbers

Difficulty: Easy · Key topics: place value, rounding, the four operations, factors and multiples, exponents, order of operations

This opening chapter resets the basics before algebra begins. It walks through the counting numbers and whole numbers on a number line, how to name and round large numbers by place value, and then rebuilds addition, subtraction, multiplication, and division from the ground up — including long division with remainders. It closes by introducing exponential notation as repeated multiplication and the order of operations (parentheses, exponents, then multiplication/division and addition/subtraction left to right) as the one rule that makes multi-step arithmetic expressions unambiguous.

Key Points:

• Whole numbers are the counting numbers (1, 2, 3, …) plus 0; they have no fractional or negative part.
• Rounding looks one place to the right of the target place to decide whether to round up or keep the digit.
• In a multiplication or division word problem, the words “product,” “quotient,” “total,” and “difference” signal which operation to use.
• a^n means a multiplied by itself n times — exponential notation, not multiplication by n.
• Order of operations: Parentheses → Exponents → Multiply/Divide (left to right) → Add/Subtract (left to right).

Memory Tip: Use “Please Excuse My Dear Aunt Sally” (Parentheses, Exponents, Multiply, Divide, Add, Subtract) to hold the order-of-operations sequence — but remember multiply/divide are one left-to-right pass, and so are add/subtract, not two separate passes.

Common Mistake: Treating “Multiply, Divide” and “Add, Subtract” in PEMDAS as strict priority order instead of left-to-right ties — in 20 ÷ 4 × 5, dividing first gives the correct 25, not multiplying first to get 1.

Important Questions:

• What is the correct order of operations for the expression 18 − 2(9 − 3)²? Parentheses first (9−3=6), then the exponent (6²=36), then multiplication (2×36=72), then subtraction: 18−72=−54.
• Why does 5³ not equal 5×3? An exponent means repeated multiplication of the base by itself, so 5³=5×5×5=125, not 5 multiplied by the exponent.

Chapter 2: The Language of Algebra

Difficulty: Easy · Key topics: variables and expressions, evaluating expressions, translating English to algebra, factors and multiples, prime factorization, least common multiple

This chapter treats algebra as a language with its own vocabulary: variables, constants, expressions, and equations, and the difference between simplifying an expression and solving an equation. It teaches evaluating an expression for a given variable value, translating everyday phrases (“the sum of,” “less than,” “twice”) into algebraic notation, and finding factors, multiples, and prime factorizations — skills the fraction and equation chapters both lean on. It ends with the least common multiple, first by listing multiples and then by prime factorization, setting up common denominators later.

Key Points:

• An expression has no equal sign and is simplified; an equation has an equal sign and is solved.
• To evaluate an expression, substitute the given number for the variable and then apply order of operations.
• “Less than” reverses word order in translation: “5 less than x” becomes x − 5, not 5 − x.
• A number’s prime factorization is unique — every whole number greater than 1 breaks into primes in exactly one way (ignoring order).
• The LCM found by prime factorization multiplies every prime factor at its highest power appearing in either number.

Memory Tip: Read translation phrases right to left when they involve “less than” or “subtracted from” — the number named first in English is written second in algebra.

Common Mistake: Translating “5 less than x” as 5 − x by writing the words in the order they appear — the correct translation is x − 5.

Important Questions:

• Translate “the difference of 20 and 4” into algebra, then evaluate it. The difference of 20 and 4 is 20 − 4, which equals 16.
• Find the prime factorization of 60. 60 = 2 × 2 × 3 × 5 (written as 2²×3×5).

Chapter 3: Integers

Difficulty: Easy · Key topics: negative numbers, absolute value, adding and subtracting integers, multiplying and dividing integers, sign rules, the division property of equality

Integers extend the number line below zero, and this chapter builds intuition for them with real contexts — temperature, elevation, and debt — before formalizing the rules. It covers absolute value as distance from zero (always non-negative), then the sign rules for all four operations: same signs add and keep the sign for addition, opposite signs subtract and take the sign of the larger absolute value, and for multiplication/division, same signs give a positive result while different signs give a negative one. It closes by solving simple equations that involve negative numbers, including the division property of equality.

Key Points:

• Absolute value |−7| means distance from 0, so |−7| = 7, always non-negative.
• Adding two negatives moves further left on the number line: −5 + (−3) = −8.
• Subtracting a number is the same as adding its opposite: a − b = a + (−b).
• Multiplying or dividing two numbers with the same sign gives a positive result; different signs give a negative result.
• The Division Property of Equality: dividing both sides of an equation by the same nonzero number keeps it balanced.

Memory Tip: “Same signs, add and keep; different signs, subtract and take the sign of the bigger number” covers all of integer addition in one line.

Common Mistake: Assuming a negative sign always makes an answer negative — −6 × (−4) = 24, positive, because the two negative signs cancel.

Important Questions:

• Simplify −18 + 7. The signs differ, so subtract 7 from 18 and keep the sign of the larger absolute value (18 is negative): −18 + 7 = −11.
• Solve y − 6 = 10. Add 6 to both sides (Addition Property of Equality): y = 16.

Chapter 4: Fractions

Difficulty: Medium · Key topics: equivalent fractions, simplifying fractions, multiplying and dividing fractions, mixed numbers, common denominators, adding and subtracting fractions, complex fractions

Fractions get a full, methodical treatment: visualizing a fraction as equal parts of a whole, simplifying by dividing out common factors (using the prime factorizations from Chapter 2), and multiplying and dividing fractions and mixed numbers, including complex fractions (a fraction stacked inside a fraction). The chapter then separates addition/subtraction with a common denominator from the harder case of unlike denominators, where students must find the least common denominator first, convert both fractions, and only then combine numerators. It ends by solving simple equations whose coefficients are fractions.

Key Points:

• Multiplying and dividing fractions never requires a common denominator; adding and subtracting always does.
• To divide by a fraction, multiply by its reciprocal (flip the second fraction and multiply).
• A mixed number converts to an improper fraction before multiplying, dividing, or applying most fraction rules.
• The least common denominator (LCD) of two fractions is the LCM of their denominators.
• A complex fraction (a fraction inside a fraction) simplifies by rewriting the division as multiplication by the reciprocal of the bottom fraction.

Practice Tip: Before adding two “ugly” fractions, write out the prime factorization of each denominator first — it makes spotting the LCD close to automatic instead of guessing.

Common Mistake: Adding numerators and denominators straight across, e.g. 1/2 + 1/3 = 2/5 — fractions must share a common denominator before the numerators can be added.

Important Questions:

• Multiply 1/8 × 2/3 and simplify. Multiply numerators and denominators directly: (1×2)/(8×3) = 2/24, which simplifies to 1/12.
• Add 3/4 + 2/6, using the least common denominator. The LCD of 4 and 6 is 12: 3/4 = 9/12 and 2/6 = 4/12, so the sum is 13/12, or 1 1/12.

Chapter 5: Decimals

Difficulty: Medium · Key topics: place value with decimals, decimal operations, rounding decimals, converting decimals and fractions, averages, ratios and rates, square roots

Decimals are framed as another way to write fractions with denominators of 10, 100, 1000, and so on, which is why the chapter opens with a money example (prices are decimals almost everywhere). It covers adding, subtracting, multiplying, and dividing decimals, converting cleanly between decimal and fraction form, and solving equations with decimal coefficients. The second half branches into applications that use decimals constantly: finding an average (mean), basic probability, writing and simplifying ratios and rates (including unit rates like miles per gallon), and simplifying square roots of perfect squares.

Key Points:

• To multiply decimals, ignore the decimal points, multiply as whole numbers, then place the point by counting total decimal places in both factors.
• To divide by a decimal, multiply both numbers by a power of 10 until the divisor is a whole number, then divide normally.
• A ratio compares two quantities of the same kind; a rate compares two different kinds of quantities (e.g., dollars per hour).
• The mean (average) is the sum of all values divided by how many values there are.
• √a asks “what number, squared, gives a?” — e.g., √81 = 9 because 9²=81.

Practice Tip: Estimate a decimal multiplication or division roughly before computing it exactly (e.g., 3.9 × 2.1 is close to 4 × 2 = 8) — it catches a misplaced decimal point instantly.

Common Mistake: Lining up decimal points incorrectly when subtracting numbers with a different number of decimal places, e.g. computing 5 − 0.35 by aligning the rightmost digits instead of the decimal points.

Important Questions:

• Divide 2.76 ÷ 11.5. Multiply both by 10 to clear the decimal in the divisor: 27.6 ÷ 115 = 0.24.
• Write 35 miles in 2 hours as a unit rate. Divide both quantities by 2 to get “per 1 hour”: 17.5 miles per hour.

Chapter 6: Percents

Difficulty: Medium · Key topics: percent as a fraction of 100, converting between percents/decimals/fractions, the percent equation, sales tax, commission, discount, simple interest, proportions

Percents are introduced as another face of the same idea as fractions and decimals — “per 100” — and the chapter builds one reusable strategy (identify the amount, the base, and the percent, then translate to an equation) that it applies across every real-world case that follows: sales tax, commission, discounts, and simple interest (using the formula I = Prt, where P is principal, r is annual rate, and t is time in years). It closes with proportions — two equal ratios — and cross-multiplication as a second way to solve percent and rate problems.

Key Points:

• “Percent” literally means “per hundred”: 45% = 45/100 = 0.45.
• The general percent equation is: percent × base = amount.
• Simple interest formula: I = Prt, where P = principal, r = annual interest rate (as a decimal), t = time in years.
• A discount is subtracted from the original price; sales tax and commission are added to or based on a price.
• In a proportion a/b = c/d, cross-multiplying gives ad = bc, which is solvable for any one unknown.

Memory Tip: Convert a percent to a decimal by moving the decimal point two places left before using it in any formula — forgetting this step is the single most common percent-problem error.

Common Mistake: Plugging a percent directly into I = Prt as a whole number (e.g., using 5 instead of 0.05 for 5% interest), which inflates the answer by a factor of 100.

Important Questions:

• Find the simple interest earned after 5 years on $1,000 at an interest rate of 4%. I = Prt = 1000 × 0.04 × 5 = $200.
• A $60 jacket is on sale for 25% off. What is the sale price? The discount is 25% × $60 = $15, so the sale price is $60 − $15 = $45.

Chapter 7: The Properties of Real Numbers

Difficulty: Medium · Key topics: rational and irrational numbers, the real number line, commutative and associative properties, the distributive property, identity and inverse properties, systems of measurement

This chapter names the full real number system — rational numbers (any number writable as a fraction of integers, including repeating or terminating decimals) and irrational numbers (like π or √2, whose decimals never terminate or repeat) together form the real numbers. It formalizes the arithmetic properties used loosely in earlier chapters: commutative (order doesn’t matter for + and ×), associative (grouping doesn’t matter), distributive (a(b+c) = ab+ac, the single most-used property in algebra), and the identity/inverse properties for addition and multiplication. It closes with U.S. and metric systems of measurement and converting between units.

Key Points:

• Rational numbers include all integers, fractions, and decimals that terminate or repeat; irrational numbers never terminate or repeat.
• Commutative Property: a+b=b+a and ab=ba — but subtraction and division are NOT commutative.
• Distributive Property: a(b+c) = ab + ac, used constantly to expand or factor expressions.
• The additive identity is 0 (a+0=a); the multiplicative identity is 1 (a×1=a).
• Every nonzero number has a multiplicative inverse (reciprocal) whose product with it is 1.

Memory Tip: “Commutative” sounds like “commute” — the numbers travel past each other and swap places; “associative” sounds like “associate” — the numbers change which group (parentheses) they associate with.

Common Mistake: Assuming subtraction is commutative like addition — 7 − 3 ≠ 3 − 7 (4 versus −4), so order matters for subtraction and division even though it never matters for addition and multiplication.

Important Questions:

• Is √16 rational or irrational, and why? Rational — √16 = 4 exactly, and 4 is a whole number (a rational number), even though it started under a radical.
• Use the Distributive Property to simplify 5(2x + 7). Distribute the 5 to each term inside the parentheses: 5(2x) + 5(7) = 10x + 35.

Chapter 8: Solving Linear Equations

Difficulty: Medium · Key topics: the addition and subtraction properties of equality, the division and multiplication properties of equality, combining like terms, variables on both sides, clearing fractions and decimals

Equation-solving, previewed in small doses in earlier chapters, becomes the main event here. The chapter builds a single mental model — an equation is a balance, and whatever is done to one side must be done to the other — and applies it in increasing complexity: one-step equations using addition/subtraction or multiplication/division properties, then multi-step equations that need combining like terms first, then equations with variables and constants on both sides (collect variable terms on one side, constants on the other), and finally equations whose coefficients are fractions or decimals, solved by multiplying through by the LCD or a power of 10 to clear them before solving.

Key Points:

• The Addition/Subtraction Properties of Equality: adding or subtracting the same value from both sides preserves the equation.
• The Multiplication/Division Properties of Equality: multiplying or dividing both sides by the same nonzero value preserves the equation.
• “Combine like terms” first, on each side separately, before doing anything else to isolate the variable.
• With variables on both sides, move all variable terms to one side and all constants to the other before isolating the variable.
• Multiplying every term of a fraction- or decimal-coefficient equation by the LCD (or a power of 10) clears the fractions/decimals in one step.

Practice Tip: After solving any equation, substitute your answer back into the ORIGINAL equation (not a simplified version) to check it — this catches sign errors and arithmetic slips before they carry into a bigger problem.

Common Mistake: Forgetting to apply an operation to every term on a side, especially when clearing a fraction or distributing a negative sign across parentheses — e.g., simplifying −(3x − 5) as −3x − 5 instead of the correct −3x + 5.

Important Questions:

• Solve 4y − 9 + 9 = 4y is an identity — solve instead 4y − 9 = 15. Add 9 to both sides: 4y = 24; divide both sides by 4: y = 6.
• Solve 5x + 8 = 14. Subtract 8 from both sides: 5x = 6; divide both sides by 5: x = 6/5.

Chapter 9: Math Models and Geometry

Difficulty: Medium · Key topics: the problem-solving strategy, money applications, angles and triangles, the Pythagorean Theorem, area and perimeter of rectangles/triangles/trapezoids, circles, volume and surface area, solving a formula for a variable

This chapter turns algebra outward, toward word problems and geometry. It opens with a five-step problem-solving strategy (read, identify what’s unknown, name it with a variable, translate to an equation, solve, and check the answer makes sense) and applies it to coin and money problems before moving into geometry: angle relationships (complementary, supplementary, triangle angle sum), the Pythagorean Theorem for right triangles, and area/perimeter formulas for rectangles, triangles, trapezoids, and circles (using π), plus volume and surface area for common solids. It ends by solving a geometry or physics formula for a specific variable — the same equation-solving skill from Chapter 8, applied to formulas instead of numbers.

Key Points:

• The Pythagorean Theorem: in a right triangle, a² + b² = c², where c is the hypotenuse.
• The angles in any triangle always sum to 180°.
• Circle formulas use π (≈3.14): circumference = 2πr, area = πr².
• Rectangle: perimeter = 2l + 2w, area = lw. Triangle area = ½bh.
• To solve a formula for a specific variable, treat every other variable as a constant and isolate the target using the same equation-solving properties as any numeric equation.

Memory Tip: Draw the picture and label it before writing any equation in a geometry word problem — a labeled sketch turns a paragraph of English into an equation almost by itself.

Common Mistake: Using the diameter where the radius is required (or vice versa) in circle formulas — the area formula needs the radius, so a given diameter must be halved first.

Important Questions:

• A right triangle has legs of 6 and 8. Find the hypotenuse. By the Pythagorean Theorem, c² = 6² + 8² = 36 + 64 = 100, so c = √100 = 10.
• Solve the formula P = 2l + 2w for w. Subtract 2l from both sides: P − 2l = 2w; divide both sides by 2: w = (P − 2l)/2.

Chapter 10: Polynomials

Difficulty: Hard · Key topics: adding and subtracting polynomials, multiplication properties of exponents, multiplying polynomials, dividing monomials, integer exponents, scientific notation, an introduction to factoring

The book’s most algebra-heavy chapter, and the clearest bridge to a first algebra course. It defines monomials, binomials, and polynomials by their number of terms, then covers adding/subtracting (combine like terms only), the product, power, and quotient rules for exponents, multiplying polynomials (including the FOIL pattern for two binomials), and dividing monomials using the quotient rule. It then extends exponent rules to negative and zero exponents, applies them to scientific notation (writing very large or very small numbers compactly), and closes with a first, gentle introduction to factoring — pulling out a greatest common factor, the reverse of distributing.

Key Points:

• Like terms in a polynomial have the exact same variable(s) raised to the exact same power(s); only like terms combine.
• Product Rule for exponents: a^m · a^n = a^(m+n) (add exponents when multiplying same-base powers).
• Power Rule: (a^m)^n = a^(mn); Quotient Rule: a^m / a^n = a^(m−n).
• Any nonzero number raised to the 0 power equals 1; a negative exponent means “reciprocal of the positive-exponent form.”
• Scientific notation writes a number as a × 10^n, where 1≤a<10 — the exponent counts how far the decimal point moves.

Practice Tip: When multiplying two binomials, say each FOIL step out loud (First, Outer, Inner, Last) until it becomes automatic — skipping a term is the single most common source of a wrong answer here.

Common Mistake: Adding exponents when the bases are different, or when the terms are being added rather than multiplied — x² + x³ does NOT simplify to x⁵; only multiplication of same-base powers adds exponents.

Important Questions:

• Multiply (x + 3)(x + 5) using FOIL. First: x², Outer: 5x, Inner: 3x, Last: 15 — combine: x² + 8x + 15.
• Simplify (2m³)⁵ using the exponent rules. Apply the power rule to both factors: 2⁵·m¹⁵ = 32m¹⁵.

Chapter 11: Graphs

Difficulty: Medium · Key topics: the rectangular coordinate system, plotting ordered pairs, graphing linear equations by plotting points, intercepts, slope

The closing chapter moves from symbols to pictures. It introduces the rectangular (x, y) coordinate system, plotting ordered pairs, and checking whether a given point is a solution to an equation in two variables. It then teaches graphing a linear equation two ways — by generating a small table of solution points, and faster, by finding just the x- and y-intercepts (where the line crosses each axis) — before formalizing slope as “rise over run,” the constant rate of change that describes how steep and in which direction a line travels.

Key Points:

• An ordered pair (x, y) is a solution to an equation if substituting both values makes the equation true.
• The x-intercept is where a line crosses the x-axis (y=0); the y-intercept is where it crosses the y-axis (x=0).
• Slope = rise/run = (change in y)/(change in x) between any two points on a line.
• A positive slope rises left-to-right; a negative slope falls left-to-right; a horizontal line has slope 0.
• A vertical line has undefined slope — division by zero (zero run) is not defined.

Practice Tip: Find the intercepts first when graphing an unfamiliar linear equation — setting x=0 then y=0 usually gives two easy points faster than building a full table of values.

Common Mistake: Reversing the coordinates of an ordered pair, plotting (y, x) instead of (x, y) — the horizontal (x) value always comes first.

Important Questions:

• Is the point (4, −2) on the x-axis or the y-axis? Neither — a point lies ON the x-axis only when y=0, and ON the y-axis only when x=0; (4,−2) has both coordinates nonzero, so it is a general point in the plane, not on either axis.
• Find the slope between the points (1, 2) and (4, 8). Slope = (change in y)/(change in x) = (8−2)/(4−1) = 6/3 = 2.

Download Prealgebra 2e PDF (Free)

Prealgebra 2e is free directly from its publisher — the official OpenStax book page offers both a free PDF download and a free online read of the complete, current text. Click below to go to the official page and choose the format you want.

How to Study This Book

Prealgebra 2e is built to be read in order, and for most students it should be. Chapters 1-3 (Whole Numbers, The Language of Algebra, Integers) are the true foundation: Chapter 2 introduces the algebra vocabulary and prime factorization that Chapters 4 and 10 both depend on, and Chapter 3’s sign rules for integers get reused in every chapter after it. Do not skip these even if the arithmetic feels familiar — the vocabulary is what changes.

Chapters 4-6 (Fractions, Decimals, Percents) are the three ways of writing “part of a whole,” and they are sequenced deliberately: fraction skills from Chapter 4 make the fraction-decimal conversions in Chapter 5 much faster, and Chapter 5’s decimal operations are used directly inside every percent formula in Chapter 6. A student who is shaky on fractions should slow down here rather than push ahead — Chapters 8 through 11 all quietly assume fraction fluency.

Chapter 7 (Properties of Real Numbers) is short but structurally important: the Distributive Property introduced here is the single most-used tool in Chapters 8 (clearing parentheses before solving) and 10 (expanding and factoring polynomials). Read it even though it looks like “just definitions” — skipping it makes Chapter 8 harder than it needs to be.

Chapter 8 (Solving Linear Equations) is the chapter this entire book has been building toward, and it is the one most directly tested on placement and entry tests. Students preparing for a timed test should over-practice the “variables on both sides” and “fraction/decimal coefficient” sections specifically, since those are where most equation-solving mistakes concentrate.

Chapter 9 (Math Models and Geometry) is an application chapter — it does not introduce new algebra, it puts Chapter 8’s equation-solving to work in word problems and geometry formulas. It is one of the more skippable chapters for a student who only needs algebra fundamentals in a hurry, but it is exactly the chapter to prioritize for anyone whose entry test includes geometry or word-problem items.

Chapters 10 (Polynomials) and 11 (Graphs) are the two chapters that reach furthest past “prealgebra” into what a first algebra course covers next. They are valuable previews, not strict requirements for finishing this book’s core arithmetic-and-equations goal — a student on a tight timeline preparing only for an arithmetic-focused entry test can treat them as optional, while anyone continuing directly into Elementary Algebra should not skip them.

The book does not cover graphing systems of two equations, inequalities, or any trigonometry — those begin in Elementary Algebra 2e and Intermediate Algebra 2e, OpenStax’s next two books in the same developmental-math series.

Used In These Programs

Prealgebra 2e is a Foundation-level book — it is not tied to one specific degree. It is commonly used as a refresher for the arithmetic and pre-algebra skills that entry tests and first-semester Foundation math courses assume, across BS Computer Science, BS Information Technology, BS Software Engineering, BBA, BS Mathematics, and any other program with a quantitative entry requirement. Browse all General Mathematics books or all Mathematics books.

Who Should Read This

This book is written for anyone whose arithmetic and basic-algebra skills need a genuine refresher before starting university-level math — students preparing for an entry test, students in a Foundation or bridging-year math course, and students who finished secondary school some time ago and want to rebuild confidence before their first BS-level math or statistics course. It assumes no prior algebra: it starts from whole-number arithmetic and builds up. It is not the right book for a student who already handles linear equations, fractions, and percents comfortably and needs calculus, discrete math, or statistics instead — that student should move straight to a book like Discrete Mathematics: An Open Introduction or one of the Calculus volumes below.

Applicable Universities

This book is useful for Foundation-level and entry-test preparation at Pakistani universities and colleges offering BS programs in Computer Science, Information Technology, Software Engineering, Business Administration, and Mathematics, including Punjab University, Virtual University, COMSATS, FAST, UET, NUST, and other HEC-recognized institutions.

FAQs

Related Books

No other prealgebra or developmental-math title is published on Freebooks.pk yet, so these are the closest published Mathematics books — not peers at the same level, but where a student typically goes after mastering the arithmetic and equation-solving skills in this book:

• Discrete Mathematics: An Open Introduction – Oscar Levin (the next foundational math step for BSCS/BSIT students, once basic algebra is solid)
• Calculus Volume 1 – Strang & Herman (OpenStax) (the natural continuation of this book’s algebra chapters, once equation-solving and graphing are comfortable)
• Active Calculus – Matthew Boelkins (2nd Edition) (a second free calculus option, useful once Prealgebra’s graphing and equation skills are in place)
• Calculus Volume 2 – Strang & Herman (OpenStax) (for later reference, once Volume 1’s material is complete)

Prealgebra 2e is the free, complete way to rebuild whole-number arithmetic, fractions, decimals, percents, and basic equation-solving before a university entry test or a Foundation-level math course. Browse more Mathematics books to continue building from here.

Prealgebra 2e, by Lynn Marecek, MaryAnne Anthony-Smith, and Andrea Honeycutt Mathis. Published by OpenStax / Rice University. Licensed under CC BY-NC-SA 4.0 (Creative Commons Attribution-NonCommercial-ShareAlike International). Free PDF download and online read at https://openstax.org/details/books/prealgebra-2e