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Square and Cube Roots. Mrs. Rauch. How do we square a number?. Can we square negative numbers?. Square Roots. Square Roots. Perfect Squares. What does cubing a number mean? . Cubing a number. To cube a number, you just multiply that number by itself 3 times
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Square and Cube Roots Mrs. Rauch
How do we square a number? • Can we square negative numbers?
Cubing a number • To cube a number, you just multiply that number by itself 3 times • Example: 3 cubed is or 3 x 3 x 3 • The little 3 means the number appears 3 times when multiplying
Practice with cubes • 4 cubed • 5 cubed • 6 cubed
Cube Roots • A cube root goes the other direction • 3 cubed is 27 so the cube root of 27 is 3 • The cube root of a number is a special value that when cubed gives the original number • The cube root of 27 is 3 because when 3 is cubed you get 27 • When you see “root” think……I know the tree but what is the root that produced it?
Practice with Cube Roots • What is the cube root of 125? • What is the cube root of 8? • What is the cube root of 1000?
The cube root sign • This is a special symbol that means “cube root”, it is the radical symbol (used for square roots) with a little 3 to mean cube root • You can use it like this…. • = 3 • We say, “the cube root of 27 is 3
Cubing Negative Numbers • When we cube 5 we get…. • When we cube -5 we get… • So can cube roots be negative?