| A | B |
|---|
| { 1, 2, 3 . . . } | the set of counting numbers |
| { 0, 1, 2, 3 . . . } | the set of whole numbers |
| { . . . -2, -1, 0, 1, 2 . . . } | the set of integers |
| Any RATIO can be written as | a fraction |
| The set of all numbers that can be written as fractions is called | the rational numbers |
| To convert a fraction to a decimal just | divide the top by the bottom |
| What kind of decimal is created when you divide the top of a fraction by the bottom and there is no remainder? | a terminating decimal |
| What kind of decimal is created when you divide the top of a fraction by the bottom and a pattern keeps repeating? | a repeating decimal |
| What 2 kinds of decimals can you get when you convert a fraction to a decimal? | terminating or repeating |
| What is the set of all terminating and repeating decimals called? | rational numbers |
| What is the set of all non-terminating, non-repeating decimals called? | irrational numbers |
| 1/2 converts to what type of decimal? | terminating |
| 1/3 converts to what type of decimal? | repeating |
| Irrational numbers are easy to spot because they look | wacky and strange |
| If A = { 1, 2, 3 } and B = { 3, 4, 5 } what is A U B ? | { 1, 2, 3, 4, 5 } |
| If A = { 1, 2, 3 } and B = { 3, 4, 5 } what is A intersect B ? | { 3 } |
| Members of the set A U B are the members of | either { A } OR { B } |
| Members of the set A intersect B are the members of | { A } AND { B } |
| The word associated with the UNION of sets is | OR - ( its elements are either elements of { A } OR elements of { B } ) |
| The word associated with the INTERSECTION of sets is | AND - ( its elements are elements of { A } AND elements of { B } ) |
| Members of a set are also called | elements of the set |
| The set with NO members is called | the empty set |
| The symbol for the empty set is | The Greek letter Phi |
| Can the union of two non-empty sets be the empty set? | No - the union will be all the elements of both sets |
| Can the intersection of two non-empty sets be the empty set? | Yes - if they have no common elements |
| Sometimes it is easier to visualize the relationships among sets by drawing | a Venn diagram |
| In a Venn diagram all of the sets are subsets of | the universal set |
| If I am discussing the set of pure-bred Poodles and the set of pure-bred German Shepherds then the universal set might be | the set of all dogs |
| A is a subset of B means | every member of { A } is a member of { B } |
| Is the set of Poodles a subset of the set of dogs? | YES - because every Poodle is a dog |
| Is the set of dogs a subset of the set of Poodles? | NO - because every dog is not a Poodle |
| Is { 0 } a subset of { whole numbers } ? | YES because 0 is a memeber of the set { 0, 1, 2, 3 . . .} |
| { rational numbers } is a subset of { real numbers } True or False? | True - every number set that we study in this class is a subset of the real numbers |
| { rational numbers } U { irrational numbers } | { real numbers } (Because every real number is either rational or irrational) |
| { rational numbers } intersect { irrational numbers } | The empty set (Because no number is both rational and irrational) |
| What do you do when you describe a set using the ROSTER method? | List the elements of the set |
| What set is a subset of every other set? | The empty set |
| Every set is a subset of | itself |
