The Real Numbers

Mathematics, Grade 8

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Numbers used in everyday life are real numbers. Real numbers are used to measure quantities such as temperature, speed of a car or volume of liquid in a cup. Real numbers are classified as either rational or irrational. Properties of Real Numbers Rational Numbers Irrational Numbers Property Property Addition Addition Multiplication Multiplication Associative Commutative Identity Inverse Distributive a + b = b + a a + 0 = a a 1 = a a b = b a a + (b + c) = (a + b) + c a + (-a) = 0 (-a) + a = 0 a (b c) = (a b) c (b + c) a = ba + ca or If a = 0, then a = 1 or a 1 a 1 a = 1 b a The Density Property is an important property of real numbers. It states that between any two real numbers there’s another real number. Rational numbers can be written as a ratio of two integers, such as , where b is not zero. Rational numbers can also be written as a decimal that is either a terminating or repeating decimal. Real numbers that are not rational are irrational. Irrational numbers cannot be written as ratios. The decimal form of irrational numbers neither repeats nor terminates. any number that has a position on a number line Ratio Form Decimal Form 0.27272727.... or (0.2727) 0.375 3.141592654....... 2.718281828....... 1.4142135....... 4.0 8 3 11 3 16 2 e Integers -3, -2, -1, 0, 1, 2, 3 Whole numbers 0, 1, 2, 3... Natural numbers 1, 2, 3, 4, 5... Real Numbers Examples: Examples: and a (b + c) = ab + ac Irrational Numbers Rational Numbers non-terminating, non-repeating decimals any square root that is not a perfect root © Copyright NewPath Learning. All Rights Reserved. 93-4803 www.newpathlearning.com The Real Numbers
Numbers used in everyday life are . Real numbers are used . Real numbers are classified as either rational or irrational . Properties of Real Numbers Rational Numbers Irrational Numbers Property Property Addition Addition Multiplication Multiplication Associative Commutative Identity Inverse Distributive The Density Property is an important property of real numbers. It states that . Rational numbers can be written as Rational numbers can also be written as Real numbers that are not rational are irrational. Irrational numbers cannot be written as ratios. The decimal form of irrational numbers neither repeats nor terminates. Real Numbers Key Vocabulary Terms associative property commutative property decimal distributive property identity property integers inverse property irrational numbers natural numbers non-terminating decimal ratio rational numbers real numbers square root terminating decimal whole number . . . . . . Irrational Numbers Rational Numbers © Copyright NewPath Learning. All Rights Reserved. 93-4803 www.newpathlearning.com The Real Numbers \|xiBAHBDy01690ozX