330 likes | 536 Views
ALGEBRA TILES. The University of Texas at Dallas. INTRODUCTION. Algebra tiles can be used to model algebraic expressions and operations with algebraic expressions. There are three types of tiles: 1. Large square with x as its length and width.
E N D
ALGEBRA TILES The University of Texas at Dallas
INTRODUCTION • Algebra tiles can be used to model algebraic expressions and operations with algebraic expressions. • There are three types of tiles: 1. Large square with x as its length and width. 2. Rectangle with x and 1 as its length and its width 3. Small square with 1 as its length and width. x 1 1 x 1 x The University of Texas at Dallas
INTRODUCTION • Each tile represents an area. x Area of large square = x (x) = x2 x 1 x Area of rectangle = 1 (x) = x 1 1 Area of small square = 1 (1) = 1 The University of Texas at Dallas
INTRODUCTION • Does an x-tile need to be any particular length? • Does its length matter? • x-tile does not have to be a particular length because it represents a variable. Its length does not matter. NOTE FOR TUTOR The University of Texas at Dallas
ALGEBRAIC EXPRESSIONS • To model 2x2, you need 2 large squares x2 x2 The University of Texas at Dallas
AGEBRAIC EXPRESSIONS • To model x2 + 3x, you need 1 large square and 3 rectangles x2 x x x The University of Texas at Dallas
ALGEBRAIC EXPRESSIONS • How would you model 2x2 + x + 4? ANSWER x2 x2 x 1 1 1 1 The University of Texas at Dallas
ALGEBRAIC EXPRESSIONS • What algebraic expression is modeled below? ANSWER 2x + 3 The University of Texas at Dallas
ALGEBRAIC EVALUATION • Suppose x is standing for 4. What is the value of 2x +3 ? (2x means 2 times x). • 2x +3 = 2 (4) +3 = 8 +3 = 11 The University of Texas at Dallas
ALGEBRAIC EVALUATION • What is the value of 2x + 3 if x = 8? ANSWER • 2 (8) + 3 • 16 + 3 • 19 2x + 3 =19 if x = 8 The University of Texas at Dallas
ALGEBRAIC EVALUATION • Remember that a variable can represent many number. The University of Texas at Dallas
ALGEBRAIC EVALUATION • Find the value of this expression using these values of x. • x = 2 • x = 5 • x = 10 X X X 1 1 1 1 1 ANSWER The University of Texas at Dallas
ALGEBRAIC EVALUATION • The algebraic expression for the tiles is 3x + 5 • If x = 2 • 3 (2) + 5 • 6 + 5 = 11 • 2) If x = 5 • 3 (5) + 5 • 15 + 5 = 20 3) If x = 10 3 (10) + 5 30 + 5 = 35 The University of Texas at Dallas
ALGEBRAIC OPERATIONS • We can use algebra tiles to model adding, subtracting, multiplying, and dividing algebraic expressions The University of Texas at Dallas
ALGEBRAIC ADDITION • To use algebra tiles to model 3 + (2x + 4) represent each addend with tiles. 3 + 2x + 4 2x + 7 = x x x x = 1 1 1 + 1 1 1 1 1 1 1 1 1 1 1 Combine the tiles The University of Texas at Dallas
ALGEBRAIC ADDITION • Find the sum: • 2x + (5x + 4) ANSWER x x x x x x x + x x x x x = 1 1 1 1 x x 1 1 1 1 2x + (5x + 4) = 7x + 4 The University of Texas at Dallas
ALGEBRAIC ADDITION • Find the sum: • (x + 3) + (2x + 4) ANSWER x x x x x x + 1 1 1 = 1 1 1 1 1 1 1 1 1 1 1 (x + 3) + (2x + 4) = 3x + 7 The University of Texas at Dallas
ALGEBRAIC ADDITION • Find the sum: • (x2 + 3) + (2x2 + x + 2) ANSWER x2 x2 + x2 x2 = x2 x 1 1 1 x 1 1 1 1 1 x2 1 1 (x2 + 3) + (2x2 + x +2) = 3x2 + x + 5 The University of Texas at Dallas
ALGEBRAIC SUBTRACTION • To use algebra tiles to model subtraction, represent each expression with tiles. Put the second expression under the first. • (5x + 4) – (2x + 3) Now remove the tiles which match in each expression. 5x + 4 x x x x x The answer is the expression that is left. 1 1 1 1 x x 2x + 3 1 1 1 (5x + 4) – (2x + 3)= 3x +1 The University of Texas at Dallas
ALGEBRAIC SUBTRACTION • Use algebra tiles to find the difference. • (8x + 5) – (6x + 1) ANSWER 8x + 5 x x x x x x x x 1 1 1 1 1 6x + 1 - x x x x x x 1 (8x + 5) – (6x + 1) = 2x + 4 The University of Texas at Dallas
ALGEBRAIC SUBTRACTION • Find the difference. • (6x + 1) – (3x) ANSWER 6x + 1 x x x x x x 1 3x x - x x (6x + 1) – (3x) = 3x +1 The University of Texas at Dallas
ALGEBRAIC SUBTRACTION • Find the difference. • (5x + 6) – (5x) ANSWER 5x + 6 x x x x x 1 1 1 1 1 1 - 5x x x x x x (5x + 6) – (5x) = 6 The University of Texas at Dallas
ALGEBRAIC SUBTRACTION • Use algebra tiles to find the difference. • (3x2 + 4x + 5) – (x2 + 3x + 4) 3x2 + 4x + 5 ANSWER x2 x2 x2 x x x x 1 1 1 1 1 x2 + 3x + 4 - x2 x x x 1 1 1 1 (3x2 + 4x + 5) – (x2 + 3x + 4) = 2x2 + x + 1 The University of Texas at Dallas
ALGEBRAIC MULTIPLICATION • To multiply using algebra tiles, lay the factors in a rectangular array. • Ex: 2 (x + 3) x + 3 2 x Fill in this space to form a rectangle. And the result is your answer 1 1 1 x x 1 1 1 1 1 1 1 1 2 (x + 3) = 2x + 6 The University of Texas at Dallas
ALGEBRAIC MULTIPLICATION • Find the product. • x (x + 2) ANSWER (x + 2) x x 1 1 x2 x x x x (x + 2) = x2 + 2x The University of Texas at Dallas
ALGEBRAIC MULTIPLICATION • Find the product. • 2x (x + 3) ANSWER (x + 3) 2x x 1 1 1 x2 x x x x x x2 x x x 2x (x + 3) = 2x2 + 6x The University of Texas at Dallas
ALGEBRAIC MULTIPLICATION • Find the product. • (x+2) (x + 4) ANSWER (x + 4) x +2 x 1 1 1 1 x2 x x x x x x x 1 1 1 1 1 1 1 1 1 1 (x+2) (x + 4) = 2x2 + 6x + 8 The University of Texas at Dallas
ALGEBRAIC MULTIPLICATION • Find the product. • (x+3) (2x + 1) ANSWER (2x + 1) x +3 x x 1 x2 x2 x x x x x x 1 1 x x 1 1 1 1 (x+3) (2x + 1) = 2x2 + 7x + 3 The University of Texas at Dallas
ALGEBRAIC DIVISION • To model division using algebra tiles, use a rectangular array like you did for multiplication except the dividend (the numerator) goes where your multiplication answer was The University of Texas at Dallas
ALGEBRAIC DIVISION • Ex: Fill in this space to complete the array. This is your answer! 2 x x 1 1 1 x x x x 1 1 1 1 4x + 6 1 1 1 1 The University of Texas at Dallas
ALGEBRAIC DIVISION • Find the quotient: ANSWER 3 x x x 1 (9x + 3) x x x x x x 1 1 x x x 1 1 1 1 The University of Texas at Dallas
ALGEBRAIC DIVISION 6x2 + 3x 3x • Find the quotient: ANSWER 3x x x 1 (6x2 + 3x) x x2 x2 x x x2 x2 x 6x2 + 3x 3x = 2x + 1 x x2 x2 x The University of Texas at Dallas
ALGEBRAIC DIVISION 2x2 + 6x + 4 x + 2 • Find the quotient: ANSWER x+ 2 x x 1 1 (2x2 + 6x + 4) x x2 x2 x x x x x x 1 1 1 1 1 1 2x2 + 6x + 4 x + 2 = 2x + 2 The University of Texas at Dallas