Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. 1.5 Multiplying Whole Numbers and Area

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 22 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall = 5 ∙ 4 = 20 5 fours factor product Multiplication is repeated addition with a different notation. Multiplication

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 33 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Multiplication Property of 0 The product of 0 and any number is 0. 9  0 = 0 0  6 = 0

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 44 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Multiplication Property of 1 The product of 1 and any number is that same number. 9  1 = 9 1  6 = 6

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 55 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Commutative Property of Multiplication Changing the order of two factors does not change their product. 6 3 = 18 and 3 6 = 18

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 66 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Associative Property of Multiplication Changing the grouping of factors does not change their product. 5 ( 2 3) = 5 6 = 30 and (5 2) 3 = 10 3 = 30

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 77 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Distributive Property Multiplication distributes over addition. 5(3 + 4) =

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 88 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Area 1 square inch 11 11 5 inches 3 inches Area of a rectangle = length  width = (5 inches)(3 inches) = (5 inches)(3 inches) = 15 square inches = 15 square inches

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 99 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Remember that (distance around a plane figure) is measured in units. Area (space enclosed by a plane figure) is measured in square units. Remember that perimeter (distance around a plane figure) is measured in units. Area (space enclosed by a plane figure) is measured in square units. 5 inches 4 inchesRectangle 5 inches + 4 inches + 5 inches + 4 inches = 18 inches Perimeter = Area = (5 inches)(4 inches) = 20 square inches Helpful Hint

Martin-Gay, Prealgebra & Introductory Algebra, 3ed 10 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. There are several words or phrases that indicate the operation of multiplication. Some of these are as follows: Key WordsExamplesSymbols multiply multiply 4 by product the product of 2 and times 7 times Multiplication Words