2. Adding and Subtracting Whole Numbers and Perimeter 3 + 4 = 7 addend addend sum Section 1.3

3. Addition Property of 0 The sum of 0 and any number is that number. 8 + 0 = 8 and 0 + 8 = 8 2 Martin-Gay, Prealgebra, 5ed

4. Commutative Property of Addition Changing the order of two addends does not change their sum. 4 + 2 = 6 and 2 + 4 = 6 3 Martin-Gay, Prealgebra, 5ed

5. Associative Property of Addition Changing the grouping of addends does not change their sum. 3 + (4 + 2) = 3 + 6 = 9 and (3 + 4) + 2 = 7 + 2 = 9 4 Martin-Gay, Prealgebra, 5ed

6. Subtraction Properties of 0 The difference of any number and that same number is 0. 9 - 9 = 0 The difference of any number and 0 is the same number. 7 - 0 = 7 5 Martin-Gay, Prealgebra, 5ed

7. A polygon is a flat figure formed by line segments connected at their ends. Geometric figures such as triangles, squares, and rectangles are called polygons. rectangle square triangle 6 Martin-Gay, Prealgebra, 5ed

8. Finding the Perimeter of a Polygon The perimeter of a polygon is the distance around the polygon distance around the polygon. 7 Martin-Gay, Prealgebra, 5ed

9. Descriptions of problems solved through addition may include any of these key words or phrases: Key Words ExamplesSymbols added to 3 added to 9 3 + 9 plus 5 plus 22 5 + 22 more than 7 more than 8 7 + 8 total total of 6 and 5 6 + 5 increased by 16 increased by 7 16 + 7 sum sum of 50 and 11 50 + 11 8 Martin-Gay, Prealgebra, 5ed

10. Descriptions of problems solved by subtraction may include any of these key words or phrases: Key Words ExamplesSymbols subtract subtract 3 from 9 9 - 3 difference difference of 8 and 2 8 - 2 less 12 less 8 12 - 8 take away 14 take away 9 14 - 9 decreased by 16 decreased by 7 16 - 7 subtracted from 5 subtracted from 9 9 - 5 9 Martin-Gay, Prealgebra, 5ed

11. Be careful when solving applications that suggest subtraction. Although order does not matter when adding, order does matter when subtracting. For example, 10 – 3 and 3 – 10 do not simplify to the same number. Helpful Hint 10 Martin-Gay, Prealgebra, 5ed

12. Since subtraction and addition are reverse operations, don’t forget that a subtraction problem can be checked by adding. Helpful Hint 11 Martin-Gay, Prealgebra, 5ed

13. Reading a Bar Graph The graph shows the ratings of Best Picture nominees since 1984. Source: The internet Movie Database and Cuadra Associates Movie Star Database, 2003. Number of Best Picture Nominees 0 2 16 25 52 Ratings 12