Mr. Scott’s Study Sheet Test 1 The test will cover everything that was on the first Quiz (fractions, decimals & percents), as well as everything on this study sheet (sets of numbers, square roots, & properties of numbers). Sets of Numbers Natural Numbers (Counting Numbers): 1, 2, 3, 4, 5, 6… Wh0le Numbers: 0, 1, 2, 3, 4, 5, 6, 7… Integers: …-4, -3, -2, -1, 0, 1, 2, 3, 4, 5… Rational Numbers: Any number that can be 𝑎 expressed as a fraction of two integers 𝑏 (where b≠0). This includes: fractions, repeating decimals, terminating decimals. REMEMBER: the square root of a perfect square would be considered rational. For example: √49 = 7 Irrational Numbers: Any type of number that cannot be expressed as a fraction of two integers. This includes: non-repeating, non-terminating decimals. For example, a number, such as 0.1385875832382485895845992….Notice how it does not repeat, but it also does not end. π is an irrational number because it is a never ending decimal. Any square root of a non-perfect square is an irrational number. Square Roots The square of a number is the product when a number is multiplied by itself. Examples: The square of 4 is 42 = 16 The square of 10 is 102 = 100 The square of 14 is 142 = 196 Don’t confuse this with square root!!! The square root of a number is the number that when multiplied by itself equals a given number. Examples: The square root of 225 is √225 = 15 The square root of 196 is √196 = 14 The square root of 81 is √81 = 9 A perfect square is a number that is a square of an integer. Please memorize all of the perfect squares/square roots up to 225. √1 = 1 √81 = 9 √25 = 5 √169 = 13 √4 = 2 √100 = 10 √36 = 6 √196 = 14 √9 = 3 √121 = 11 √49 = 7 √225 = 15 √16 = 4 √144 = 12 √64 = 8 How do we approximate a square root? If we have a non-perfect square root, we can approximate it to the nearest whole number. Example 1: √17 The closest perfect square to 17 is 16. Since √16 = 4, then √17 ≈ 4 Example 2: √99 The closest perfect square to 99 is 100. Since √100 = 10, then √99 ≈ 10 How do we evaluate expressions with square roots? Substitute in your variables. Solve all of your square roots first. Example 1: Let x = 3, y = 6, and z = 9 Solve: Notice how √9 9 √𝑥+𝑦 𝑧 = √3 + 6 9 √9 9 3 1 93 does NOT equal 1. We solved the square root FIRST, then simplified. Properties of Numbers Commutative Property of Addition: Commutative Property of Multiplication: a+b+c=c+b+a axbxc=cxbxa Associative Property of Addition: Associative Property of Multiplication: (a + b) + c = a + (b + c) (a x b) x c = a x (b x c) Distributive Property: a (b + c) = ab + ac a (b – c) = ab – ac Identity Property of Addition: Identity Property of Multiplication: a+0=a ax1=a Inverse Property of Addition: Inverse Property of Multiplication: a + (-a) = 0 1 ax𝑎=1 Zero Product Property: ax0=0 Remember! The commutative, associative, identity, and inverse property are for addition and multiplication only!