Learn vocabulary, terms, and more with flashcards, games, and other study tools. See more ideas about Real numbers, Irrational numbers and Real number system. Create New Sheet Share Select a Worksheet Version 1 Version 2 Version 3 Version 4 Version 5 Version 6 Version 7 Version 8 Version 9 Version 10 Grab 'em All Create New Sheet. The rules for. rational numbers and order of operations. 10 Questions. Rational and Irrational numbers powerpoint NS1 8th grade Math 2015 Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. This is the typically format of the practice tests we have seen going around. 3030030003… and 0. The difference between rational and irrational numbers can be drawn clearly on the following grounds Rational Number is defined as the number which can be written in a ratio of two integers. If the set of irrational numbers is denoted by H, then. The wholes are just the naturals with zero thrown in. Printable worksheets and online practice tests on Number System for Grade 9. Some of the worksheets for this concept are Work classifying numbers which, Concept 13 rational irrational numbers, Sets of real numbers date period, Numbers rational and irrational, Rational and irrational numbers 2, Irrational numbers, First published in 2013 by the university of utah in, Work 1 rational and irrational numbers. Difference between rational and irrational numbers Although rational numbers can go on and on with an infinite amount of numbers, they nonetheless have a pattern. A rational number is a number that can be written as a ratio of two integers. 9th Grade Math. 5 Identify. Comparison between Rational and Irrational Numbers. Whole numbers comprise of all natural numbers and zero. Rational number worksheets, 8th Grade Math TAKS Formula chart, math trivia algebra, simplifying algebraic expressions calculator. Other irrational numbers include the square root of 3, the square root of 5, pi, e, and the golden ratio. Whenever you have to have service with math and in particular with rational numbers calculator or algebra exam come pay a visit to us at Polymathlove. Showing top 8 worksheets in the category - Grade 9 Rational Numbers. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Ninth Grade (Grade 9) Rational and Irrational Numbers questions for your custom printable tests and worksheets. High school math for grade 10, 11 and 12 math questions and problems to test deep understanding of math concepts and computational procedures are presented. Compare and order rational numbers (positive and negative integers, fractions, decimals ). org is simply the excellent place to head to!. irrational numbers worksheet math grade worksheets rational awesome best vs s images and workshe. Rational Numbers A Multi-Part Lesson 12-1 PART B C Main Idea Compare and order fractions, decimals, and percents. Materials: Color by Classifying worksheet, blue, green, yellow, and black coloring utensils. Free 7th Grade Math Worksheets for Teachers, Parents, and Kids. Worksheets are Disputing irrational beliefs, 12 irrational beliefs albert ellis, Structured disputing of irrational beliefs, Techniques for disputing irrational beliefs, Rebt self help form, Activity reframing irrational thoughts purpose estimated time, Irrational distorted and pessimistic thinking patterns. Free Math Worksheets for Grade 7 - Homeschool Math. Whole numbers comprise of all natural numbers and zero. When we put together the rational numbers and the irrational numbers, we get the set of real numbers. You have solved polynomial equations and found that their roots are included in the set of complex numbers. √4 - rational because in standard form this number is 2 which is a natural, whole, integer. Rational Numbers, irrational Numbers, rationalize irrational numbres, operation on real numbers, laws of exponents, rules of indices and Real Numbers. 1 Know that the numbers that are not rational are called irrational. For example, -2, 7, 3/4, 0. Sep 18th, 2019. The Standards for Mathematical Practice describe the varieties of expertise, habits of minds, and productive dispositions that educators seek to develop in all students. org are unblocked. Questions on Rational Numbers. The set of integers does not include decimals or fractions. Learn what rational and irrational numbers are and how to tell them apart. If you're behind a web filter, please make sure that the domains *. Suppose that the sum of a and b is a rational number, c. Real Number Chart LSC-O Learning Center (409) 882-3373ℝ. Real Number Chart LSC-O Learning Center (409) 882-3373ℝ. The number 8 is a rational number because it can be written as the fraction 8/1. This question basically ASKS for indirect proof. New Online Test. Watch the video (Level 2: Rational & Irrational #s ) Complete the Notes & Basic Practice Check the Key and Correct Mistakes 2. 2: Use rational approximations of irrational numbers to compare the size of irrational numbers, plot them approximately on a number line, and estimate the value of expressions involving irrational numbers. 28) Find the rational number between: 1) 3 and 4 2) -7 and -6 29) Find three rational numbers between: 1) -5 and 8 2) ( -1/3 ) and (1/2) 30) State whether true or false: (practice worksheet on rational numbers) 1) Absolute value of a rational number is either positive or 0. The term is a whole number. Ninth Grade (Grade 9) Rational and Irrational Numbers questions for your custom printable tests and worksheets. org are unblocked. The rules for. So, 2, 5/11, -5. RATIONAL NUMBER- A number that can be written as a fraction, where the bottom is not equal to zero. 3010010001…, a rational will be 0. Descending Order of Rational Numbers Worksheet. An irrational number is a number which cannot be expressed in a ratio of two integers. 8th Grade Unit 2 1 Color by Classifying Objective: Students will classify numbers. On a number line, positive numbers are to the right of 0, and negative numbers are to the left of 0. Many people are surprised to know that a repeating decimal is a rational number. We offer a huge amount of good reference material on subject areas ranging from equations to geometry. com and read and learn about operations, mathematics and plenty additional math subject areas. 1 Express rational numbers as terminating or repeating decimals. 2) The sum of rational number and irrational number is an irrational-number. Eighth Grade (Grade 8) Rational and Irrational Numbers questions for your custom printable tests and worksheets. Irrational numbers-An irrational number is a number that cannot be expressed in the form of a/b, where "a" and "b" are integers and b ≠ 0. Rational Numbers Worksheet Grade 6. WORKSHEET - COMPARE AND ORDER RATIONAL NUMBERS www. Real numbers are mainly classified into rational and irrational numbers. Download Worksheets for Grade 8, Module 7, Lesson 11. Comparing irrational numbers worksheet - Questions. Find the width of a rectangle if its length is 5 more than the width and its perimeter is 90 cm. Rational Numbers are any real numbers that can be expressed as a simple fraction or ratio. These tools will help you. Displaying all worksheets related to - Irrational Beliefs. 22) 23) 24) 25). Lesson 16: Rational and Irrational Numbers. NCERT Grade 9 Maths Chapter 1, Number Systems, comes under the Unit of Number Systems. All of the numbers that we use in everyday life are real numbers. This is a comprehensive collection of free printable math worksheets for grade 7 and for pre-algebra, organized by topics such as expressions, integers, one-step equations, rational numbers, multi-step equations, inequalities, speed, time & distance, graphing, slope, ratios, proportions. Printable worksheets and online practice tests on Rational Numbers for Grade 8. Students will be expected to know relationships among fractions, decimals, and percents given a real-world context. com and discover graphing linear equations, practice and plenty of additional algebra subject areas. Problems on Irrational Numbers. Background Knowledge: Students should be familiar with various sets that numbers can be classified in (natural, whole, integer, rational, irrational, real, not real). Write a story that uses addition, subtraction, multiplication, or division of rational numbers. Identifying Rational And Irrational Numbers Worksheet - Switchconf Worksheets For All Download And Share Worksheets Free On. emathematics. NCERT Exemplar Class 8 Maths is very important resource for students preparing for VIII Board Examination. These Radical Worksheets are appropriate for 5th Grade, 6th Grade, 7th Grade, and 8th Grade. Talking related with Rational Numbers Worksheets Grade 6, we've collected particular variation of photos to complete your references. Pre-Algebra Page 9 Integers and Rational Numbers 7. Irrational numbers-An irrational number is a number that cannot be expressed in the form of a/b, where “a” and “b” are integers and b ≠ 0. 8th Grade Rational Numbers. Which statement is false? A Some integers are irrational. In eighth grade, students are introduced to irrational numbers, rounding out their understanding of the real number system before learning about complex numbers in high. (iv) There are numbers which cannot be written in the form p/q , q ≠ 0 , p, q both are integers. The pre-algebra worksheets provide simple number sentences in the form of equations with missing values, and the students fill in the answer. 1) The student represents and uses rational numbers in a variety of equivalent forms. That is what a rational number is. Students learn that the following number sets represent rational numbers: natural numbers, whole numbers, integers, fractions, terminating decimals, and repeating decimals. Download Free Pre-Algebra > Rational Number Worksheets Below: All worksheets are free to download and use for practice or in your classroom. Number properties worksheet, Rational numbers worksheet, Irrational numbers worksheet, Math Reading Science Tests for Grades , Practice Sample Test, Free Online Worksheets. In other words, a fraction is formed by dividing one integer by another integer. Because the learning of these topics is integral to the learning. Identifying Rational And Irrational Numbers. Learn what rational and irrational numbers are and how to tell them apart. The rational number 1 is the multiplicative identity for rational number. Printable Worksheets And Lessons. Sample Grade 9 Number System worksheet : Printed. 3, -5/2, 3. For example, by truncating the decimal expansion of √2. Explain why the sum or product of two rational numbers is rational; that the sum of a rational number and an irrational number is irrational; and that the product of a nonzero rational number and an irrational number is irrational. 2) Product (Multiplication) formula of radicals with equal indices is given by. The Rational Number System Worksheet Solutions. All negative integers and whole numbers make up the set of integers. Common Core Math Worksheets - K-12. Shirleen Luttrell algebra course for a combined seventh and eighth grade class. Problems on Irrational Numbers. Rational numbers may seem like a tough subject to young mathematicians; this activity allows them to practice with multiple types of rationals and irrationals to become more familiar with this category. Example: 1 1. About "Comparing irrational numbers worksheet" Comparing irrational numbers worksheet : Worksheet on c omparing irrational numbers is much useful to the students who would like to practice problems on irrational numbers. − 10 40 = − 0. Examples of irrational numbers include and π. DA: 25 PA: 22 MOZ Rank: 75 Rational and Irrational Numbers - factmonster. Displaying all worksheets related to - Identify Numbers To 0. com is an online resource used every day by thousands of teachers, students and parents. The square root of is , also a rational number. 1 review before a quiz or test. Irrational means not Rational. Identifying Rational And Irrational Numbers. The number pi and square roots of non-perfect squares are examples of irrational numbers. The denominator in a Rational Number should not be 0 2. Grade 7 Learning Module in MATH from Rational And Irrational Numbers Worksheet, source: slideshare. Teacher Note about Entrance card question 1b: Students tend to define rational numbers as :”numbers that can be written as a fraction” The problem with this is that irrational numbers such as the square root of 3 are also fractions. Showing top 8 worksheets in the category - Identifying Rational And Irrational Numbers. Rational and irrational numbers. The focus is also on determining square roots of rational numbers. Some of the worksheets for this concept are , Grade 9 rational numbers and square roots, Fractions rational numbers, Summer package pre requisite algebra skills, Add subtract multiply divide rational numbers date period, Mathematics grade 9, Math 9 final, Grade 9 number system. This interactive game has 3 categories: Comparing Rational Numbers, Adding and Subtracting Rational Numbers, and Multiplying and Dividing Rational Numbers. Students of all levels will benefit. Rational Number Worksheets The following worksheets were found at WWW. These tools will help you. We carry a lot of really good reference materials on subject areas varying from long division to matrix. Number and Quantity > Key Concept:Real Numbers, Irrational Numbers and Decimal Expansion of Numbers. More Worksheet. Come to Emaths. Grade 8 - Mathematics Curriculum - Type of Numbers: Natural, Whole, Integers, Rational, Irrational & Real - Math & English Homeschool/Afterschool/Tutoring Educational Programs. Practice this lesson yourself on KhanAcademy. All negative integers and whole numbers make up the set of integers. The outside flaps cover the irrational and rational numbers. You can print off an unlimited number of worksheets and generate an unlimited number of questions related to each skill. The sum or product of rational numbers is rational. This video explains the difference between rational and irrational numbers and how to identify rational and irrational numbers. Understand informally that every number has a decimal expansion; for rational numbers show that the decimal expansion repeats eventually, and convert a decimal expansion which repeats eventually into a rational number. Comparing and Ordering Rational Numbers Definitions. Problems on Irrational Numbers. Decimal Form of Rational Numbers - [worksheet] Model each of the following calculations with base ten blocks. mathematics number system rational and irrational numbers. All the Algebra help you need right here, and it'sl free. 7th Grade Worksheets & Other Resources. For example, by truncating the decimal expansion of √2. Prove that any irrational number multiplied by any non-zero rational number is equal to some irrational number. For example, by truncating the decimal expansion of √2. Rational numbers-A ration number is a number that can be expressed in the form a/b, where "a" and "b" are integers and "b" is not equal to 0. Search Search. 22) 23) 24) 25). Solving problems with rational numbers in decimal form. You will need one for each student. 3 Solve real world and mathematical problems involving the four operations with rational numbers Glencoe Math Accelerated Chapter 3 Larson Pre Algebra Chapter 5 5 days Integers and Rational Numbers 8. RATIONAL NUMBER- A number that can be written as a fraction, where the bottom is not equal to zero. All the Algebra help you need right here, and it'sl free. V s hMdaqd oeM DwUiht aht wIVnrf8ipn mint beg APlJg Uexb irSa G i1H. Additive inverse of 0 is 0 itself; The multiplicative inverse of the rational number is a/b is b/a and vice versa. Problem Solving with Exponents and Scientific Notation 24 8. Common Core Math Worksheets - K-12. Home > Grade 8 > Rational and Irrational Numbers Rational and Irrational Numbers Directions: Using only numbers 1-8 (without repeating any number), fill in the boxes to create the following number types:. Below are the tests for each grade: When you enter the Perspectives site through the 3rd Grade link below, click on the appropriate grade and test and it will take you to the study guide you need. Sep 3, 2018- Explore ktfrmtn's board "Rational Numbers", followed by 382 people on Pinterest. A shopkeeper sells two quality of rice at rate of $ 18 per kg. Rational Numbers also include decimals that repeat or terminate (since they can be written as fractions) Powers and Square roots may be rational numbers if their standard form is a rational number. MALATI materials: Rational numbers Rational Numbers for Grade 8 and 9 Some general remarks: • Research in Grades 8 and 9, locally and internationally, has shown that learners have a poor conception of rational numbers e. Rational and Irrational Numbers. Comparing irrational numbers worksheet - Questions. Number system involves exploring the following aspects: scientific notations (negative and positive powers of 10), exponents, approximation, ratios, roots, estimation, rational and irrational number operations, negative and positive exponents, add and. Rational and Irrational Numbers. net 6 First, write all the numbers as decimals. 9th Grade Math. The term is a whole number. Irrational Beliefs. rational numbers, we now know that not all numbers are rational. This step of introducing equations without variables can be a gentle first step into the world of finding missing values using algebraic manipulations. neither rational nor irrational number: New Worksheet. An Irrational Number is a real number that cannot be written as a simple fraction. Improve your math knowledge with free questions in "Identify rational and irrational numbers" and thousands of other math skills. Recognize that the decimal form of a rational number either terminates or repeats. org are unblocked. 9th grade Numbers Graphic Organizers Resources & Lesson Plans from Rational And Irrational Numbers Worksheet, source: teacherspayteachers. g-½=½ Compare and order rational numbers. Rational Numbers Worksheet Grade 6. Ninth Grade (Grade 9) Rational and Irrational Numbers questions for your custom printable tests and worksheets. Sample Grade 9 Number System worksheet : Printed. All the Algebra help you need right here, and it'sl free. How to find out if a radical is irrational There are a couple of ways to check if a number is rational: a. The next type of number is the "rational", or fractional, numbers, which are technically regarded as ratios (divisions) of integers. 3030030003… and 0. Worksheet #6 Fractions: Mixed Numbers Identify which of the following are improper fractions. Grade 9 math printable worksheets, online practice and online tests. What is the purpose of this document? To increase student achievement by ensuring educators understand specifically what the new standards mean a student must know, understand and be able to do. Important questions in Number systems with video lesson. By the time students enter eighth grade, students should have a strong grasp on operating with rational numbers, which will be an underlying skill in many algebraic concepts. Moving between different representations of rational and irrational numbers. For example, v2/3 is not a rational number, because 2 is not a perfect square. Rational numbers worksheet 6th grade. Rational & Irrational Numbers - ICSE Grade 9 MATHS Online Study Material - Get Free Sample Papers, Board Paper Solutions, Revision Quizzes, Video Lessons & Sample Tests on Brainnr. Paste your number strip on the board, or have a number line started on the overhead machine. Solving problems with rational numbers in fraction form. Chapter 3 Practice Test: Rational Numbers Multiple Choice Identify the choice that best completes the statement or answers the question. Decimal Form of Rational Numbers - [worksheet] Model each of the following calculations with base ten blocks. Rewrite expressions involving radicals and rational exponents using the properties of exponents. The number 8 is a rational number because it can be written as the fraction 8/1. Algebra 1 Here is a list of all of the skills students learn in Algebra 1! These skills are organized into categories, and you can move your mouse over any skill name to preview the skill. Rational & Irrational Numbers. Sixth grade unit 3 rational numbers integers resources include 6ns5 6ns6 6ns7 mighty math home. Seventh grade H. Compare (√3 + 5) and (3 + √5) and write <, >, or = in between them. I imagine I can lend you a hand. Unit 9: Square & Cube Roots; Irrational Numbers Clusters: Work with radicals and integer exponents. 1 Know that numbers that are not rational are called irrational. The sum of a rational and an irrational numbers is _____ A. When you need to have help on solution or maybe elementary algebra, Mathsite. In geometry, any. , irrational numbers cannot be rational numbers and vice-versa. Showing top 8 worksheets in the category - Ordering Rational And Irrational Numbers. Help: If students do not know how to estimate irrational numbers (squares of not perfect squares) have them review Estimating Square Roots. If your 8th grader needs extra practice with these concepts, you can create your own practice problems at home, using the samples below as examples. Playing educational quizzes is a fabulous way to learn if you are in the 6th, 7th or 8th grade - aged 11 to 14. Additive inverse of 0 is 0 itself; The multiplicative inverse of the rational number is a/b is b/a and vice versa. Rationalization. If you're behind a web filter, please make sure that the domains *. Rational And Irrational Numbers Class 9 Icse. Example: 1 1. , what is his gain or loss?. Zero is a rational number but it has no reciprocal as \( \frac{q}{0} \) is not defined, where q is a rational number. Nevada Academic Content Standard What does this standard mean that a student will know and be able to do?. 75 You want to order numbers from greatest to least. Find the width of a rectangle if its length is 5 more than the width and its perimeter is 90 cm. Register free now. The sum or product of rational numbers is rational. A better definition is that rational numbers are "numbers that can be written as a fraction of integers". Sixth grade unit 3 rational numbers integers resources include 6ns5 6ns6 6ns7 mighty math home. a rational or an irrational number. 2, 5/11, -5. • If a real number can be written as a fraction, it is a rational number. Try our high school worksheets with your teen. 55? if a=7-4 , find the value of + 16/ in a 100 m race , A beats B by 20 m , or 4 sec. Rational numbers may seem like a tough subject to young mathematicians; this activity allows them to practice with multiple types of rationals and irrationals to become more familiar with this category. Showing top 8 worksheets in the category ordering rational numbers for 6th grade. Rational & Irrational Numbers. Problems on Rationalizing the Denominator. Solving problems with rational numbers in fraction form. Identify Numbers To 0. Math Antics has a brand new look! Find out why: ↓ Scroll down to check out our Video Lessons. How to find out if a radical is irrational There are a couple of ways to check if a number is rational: a. Zero is a rational number but it has no reciprocal as \( \frac{q}{0} \) is not defined, where q is a rational number. Students of all levels will benefit. Standards: 8. g-½=½ Compare and order rational numbers. Working with Absolute Value. Difference between rational and irrational numbers Although rational numbers can go on and on with an infinite amount of numbers, they nonetheless have a pattern. What is the purpose of this document? To increase student achievement by ensuring educators understand specifically what the new standards mean a student must know, understand and be able to do. A better definition is that rational numbers are "numbers that can be written as a fraction of integers". Our Algebra worksheets are a great addition to any home school math curriculum. 0 Unported License. com is an online resource used every day by thousands of teachers, students and parents. Grade appropriate lessons, quizzes & printable worksheets. (Real, Irrational, Rational, Integer, Whole, Natural and/or Prime number) Example: Is both a Real and a Rational number. According to the Common Core Standards, 8th grade math games should focus on three critical areas: (1) formulating and reasoning about expressions and equations, including modeling an association in bivariate data with a linear equation, and solving linear equations and systems of linear equations; (2) grasping the concept of a function and using functions to describe. If the first three sides of a quadrilateral, taken in order are 14 cm, 13 cm and 12 cm respectively, and the angle between fourth side and the third side is a right angle, find the area of the quadrilateral. Really clear math lessons (pre-algebra, algebra, precalculus), cool math games, online graphing calculators, geometry art, fractals, polyhedra, parents and teachers areas too. The Greeks first introduced Algebra in the third century and eventually it was also traced to the early Babylonians. Paste your number strip on the board, or have a number line started on the overhead machine. ) For example, 2 3, 355 113, and 7 4 are all rational numbers. Click on the free 7th grade math worksheet you would like to print or download. Converting and Ordering Rational Numbers Level: 6th Grade Pre-AP Stage 1 - Desired Results TEKS: (6. The venn diagram below shows examples of all the different types of rational, irrational nubmers including integers, whole numbers, repeating decimals and more. Download Free Pre-Algebra > Rational Number Worksheets Below: All worksheets are free to download and use for practice or in your classroom. Detailed solutions and answers to the questions are provided. Guided Lesson Explanation - Make sure students read the topic, it explains all of the problems at once. That is to. Detailed solutions and answers to the questions are provided. Real numbers include natural numbers, whole numbers, integers, rational numbers and irrational numbers. Sample Grade 9 Number System worksheet : Printed. Rational Numbers. Definition: The set of Irrational Numbers is defined by those numbers whose decimal representations never terminates or repeats. Estimate Rational Numbers. Class 9 math (India) In this chapter we'll be revisiting concepts of rational and irrational numbers and operations as well as concepts about real. Equivalent rational numbers are numbers with the same value, such as a positive 4 is Equal; to an negative 4. Irrational Numbers. irrational numbers, classifying real numbers, and comparing and ordering real numbers. This lesson is most appropriate for 9th-12th grade students. New Online Test. Guided Lesson Explanation - Make sure students read the topic, it explains all of the problems at once. Use the Rational, Irrational Numbers Lesson Plan to classify numbers and explore the difference between the decimal expansions of rational and irrational numbers. Students will be expected to know relationships among fractions, decimals, and percents given a real-world context. Cut and paste activity. Rational numbers may seem like a tough subject to young mathematicians; this activity allows them to practice with multiple types of rationals and irrationals to become more familiar with this category. You have solved polynomial equations and found that their roots are included in the set of complex numbers. 0 Unported License. org are unblocked. You can select different variables to customize these Exponents and Radicals Worksheets for your needs. A real number is a number that is somewhere on a number line, so any number on a number line that isn't a rational number is irrational. Compare the following rational numbers and tell whether they are greater than, less than, or equal to each other. The venn diagram below shows examples of all the different types of rational, irrational nubmers including integers, whole numbers, repeating decimals and more. 2: Use rational approximations of irrational numbers to compare the size of irrational numbers, plot them approximately on a number line, and estimate the value of expressions involving irrational numbers. In cases where you require assistance on a quadratic or perhaps algebra review, Roots-and-radicals. From fractions math worksheets year8 to linear inequalities, we have all the pieces included. building, rm. For more worksheet you can log on to www. 8th Grade Math Mrs. 251251251251 is a repeating decimal expansion because 251 keeps repeating in the same order. Printable Worksheets And Lessons. Irrational numbers can be found by squaring rational numbers. - Albert Einstein. DA: 25 PA: 22 MOZ Rank: 75 Rational and Irrational Numbers - factmonster. A number line can help you compare and order rational numbers. mathinthemedian Math TEKS 8th from Rational And Irrational Numbers Worksheet. Irrational numbers cannot be written as ratios of. All Real Numbers that are NOT Rational Numbers; cannot be expressed as fractions, only non -repeating, non. Flashcards. Arithmetic and Algebra Worksheets. Rationalization. By the time students enter eighth grade, students should have a strong grasp on operating with rational numbers, which will be an underlying skill in many algebraic concepts. Irrational numbers in decimal form are nonrepeating, nonterminating decimals. Instant scoring, progress tracking, & award certificates to keep your student motivated. Have students work with partners to sort the number cards into rational and irrational numbers. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Rational numbers are special because they can be written as a fraction. com and read and learn about operations, mathematics and plenty additional math subject areas. Find quality practice questions and worksheets for "Rational & Irrational Numbers" eTutorWorld's free worksheet is here to rack your brains and help you practice for your tests.