College for Research and Technology of Cabanatuan Burgos Avenue, Cabanatuan City 3100 Tel. 463-2735 e-mail: crt.cabanatuan@gmail.com LESSON 1 MATHEMATICS IN OUR WORLD How does mathematics exist? TYPES OF PATTERNS IN NATURE 1. SYMMETRY – an object is said to have symmetry when it remains unchanged after transformations such as rotations and scaling are applied into it. 2. FRACTALS – are never ending patterns that are self-similar across different scales. 3. SPIRALS – curved patterns made by series of circular shapes revolving around a central point. 4. CHAOS – simple patterns created from complicated underlying behavior. SYMMETRIES OF OUR SURROUNDINGS 1. REFLECTION SYMMETRY – mirror symmetry or line symmetry. It is made with a line going through an object which divides it into two pieces which are mirror images of each other. 2. ROTATIONAL SYMMETRY – also called radial symmetry. It is exhibited by objects when their similar parts are regularly arranged around a central axis and the pattern looks the same after a certain amount of rotation. 3. TRANSLATIONAL SYMMETRY – it is exhibited by objects which do not change its size and even if it moved to another location. Ex: moving the stem to another location does not change the patterns of the leaves SHAPES IN NATURE 1. CRYSTALS – are solid materials having a compositions enclosed and arranged in symmetrical plane surfaces, intersecting at definite angles. EX: snowflakes, Ice, Diamonds, Table salts 2. ROCK FORMATIONS – most of the stone and rocks which we usually see everyday are of irregular and various shapes. 3. ANIMAL KINGDOM – millions of kinds of animal species we have in the world are various shapes, most of which are irregular. THE FIBONACCI NUMBERS “If a single pair of rabbits will be placed in controlled area and is allowed to live and multiply, how many pairs of rabbits will be produced in a year considering that in every month, each pair bears a new pair which becomes productive from the second month and so on?” Who Was Fibonacci? European mathematician 1175-1250 Real name Leonardo of Pisa. Author of Liber abaci or Book of the Abacus. Remembered today because of Edouard Lucas One of the first people to introduce the decimal number system into Europe 1 What Is the Fibonacci Sequence? Generalized sequence of first two positive integers and the next number is the sum of the previous two, i.e. 1,1,2,3,5,8,13,21,… Why Is It Significant? Has intrigued mathematicians for centuries. Shows up unexpectedly in architecture, science and nature (sunflowers & pineapples). Has useful applications with computer programming, sorting of data, generation of random numbers, etc. Existence of Fibonacci numbers in art and nature Examples: MONALISA painting Window designs Human body Floor Tiles Churches Sunflower Pineapple General rule: An = An-1 + An-2 Where: An is the Fibonacci number An-1 is the number before An; and An-1 is the number before An-1 Note that: 0+1=1 1+1=2 1+2=3 2+3=5 3+5=8 5 + 8 = 13 Fibonacci Sequence and the Golden Ratio A remarkable property of the sequence is that the ratio between two numbers in the sequence eventually approaches the “Golden Ratio” as a limit. 1/1=1, 2/1=2, 3/2=1.5, 5/3=1.6667, 8/5=1.6, 13/8=1.625, 21/13=1.6154 Famous Irrational number phi—1.61803398… Only positive # that becomes its own reciprocal by subtracting 1 Used extensively by Ancient Greeks in architecture Ratio also shows up in many famous paintings Da Vinci studied extensively the ratio and body proportions. 2 SUMMARY Fibonacci Sequence has been around for hundreds of years. Golden Ratio has been used for thousands of years. Both concepts are still in use today and continue to interest us. LESSON 2 MATHEMATICAL LANGUAGE AND SYMBOLS LANGUAGE OF MATHEMATICS – structure used by the mathematicians to communicate mathematically. Mathematical Operation Symbols and their word expressions CHARACTERISTICS OF MATHEMATICAL LANGUAGE 1. PRECISE – make an exact and accurate expressions 2. Concise – say things briefly 3. Powerful – express complex thoughts with a comparative event ENGLISH, NOUN AND SENTENCE NOUN – a word used to identify the class of people, places or things SENTENCE – used to state complete thoughts. (one noun and one verb) Example: Janice loves mathematics (Janice and mathematics are nouns and love is verb) NOUN VERSUS SENTENCE NOUN James Manila Mango SENTENCE James is the name of her brother The capital of the Philippines is Manila The national fruit of the Philippines is Mango. Mathematical operation symbols and their word expressions OPERATION WORD EXPRESSION Add, added to, plus, the sum of, more than, the total of, increased by, going up by, bigger by Subtraction (-) Subtract, subtract from, less, minus, less than, decreased by, diminished by, take away, reduced by, the difference between Multiplication (x) Multiply, times, the product of, multiply by, times as much as Division (÷) or (/) Divide, divided by, the quotient of, the ratio of, equal amounts of, per Equation (=) Equals, is equal to, exactly as, equivalent to, as similar to Mathematical expression is a name given to mathematical object of interest. Addition (+) Example: 3 The value of the expression 1 + 2 x 3 is 7, because the expression is evaluated by first multiplying 2 and 3 and then adding 1 to the result. Mathematical sentence expresses a complete thought. Example: 1. 2. 3. 4. MATHEMATICAL EXPRESSION 6 7+6 5x6 (2 + 3) – 1 MATHEMATICAL SENTENCE 6 is an even number 7 + 6 = 13 5 x 6 = 30 (2 + 3) – 1= 4 WRITING EXPRESSION AND EXPRESSION Numbers and/or variables that are connected by operation/s is called expression. An equation usually has words like “equals”, “is equal to” or is. Example: Ten a number is fourteen. Steps in translating a mathematical phrase: Step 1. Identify the variables and/or constants Constant – ten and a number is fourteen Variable – ten and a number is fourteen Step 2. Determine the connectors. Connectors – ten and a number is fourteen. Step 3. Perform the translation of the phrase into symbols. Ten and a number is fourteen 10 + x = 14 Examples: 1. Sentence/phrase to Algebraic Expression Phrase 1. Twice as old as Vic is forty 2. Joe’s age divided by five all less than three is one 3. Sonia’s age multiplied by two is seventy – eight 4. The ratio of sixteen and the number of workers is 4 5. Jaime’s age less two is twenty-four Algebraic Expression 2v = 40 𝑥 −3=1 𝑠 2s = 78 16 =4 𝑥 J – 2 = 24 4 2. Algebraic expression to English expression 1. 2. 3. 4. 5. Algebraic expression 6 + a = 40 5b = 40 𝑐 = 40 5 2m – 4 = 10 6x + 4 = 40 English expression Six more than a number is forty Product of five and a number is 40 The quotient of a number and five is forty Twice a number less four is forty Four more than the product of six and a number is forty Some symbols that commonly used in mathematics. Symbol “>” inequality sign Word expression ….is greater than….. “<” inequality sign …..is less than….. “≠” inequality sign ….is not equal to…. “≈” approximate equal sign “∑” summation sign ….is approximately equal to…. The summation of…. “!” exclamation ….factorial “√” square root “%” percent Three dots The square root of…. …percent… Therefore… “ϵ” epsilon Subset “U" Intersection ….is an element of…. …is a subset of…. …union…. ….intersection…. LESSON 3 Use Indicates value on left is greater than the value on right Indicates value on left is smaller than the value on right Indicates that two value are different Indicates two values are close to each other Sum of many or infinitely many values Product of all positive integral up to a certain value Algebraic expressions Proportion Logical statement of mathematical proof Sets Sets Sets Sets Sample expression 3>2 2<3 x≠y x+y≈z 4! = 24 √4 2.5 % aϵA A B AUB A B PROBLEM SOLVING AND REASONING 1. INDUCTIVE REASONING – type of reasoning that comes up to a conclusion by examining specific examples. It can also use in many life situations. EXAMPLE: a. Use inductive reasoning to predict the next number in the lists. 1, 3, 6, 11,,? Solution: The first two numbers differ by 2, the second and the third by 3, the third and fourth by 2 again. It appears that when two numbers differ by 2, the next difference would be 3, followed again by 2, then 5 by 3. Since the difference between 8 and 11 is 3, we predict the next number to 11 to be a number 2 more than 11, which is 13. b. If n is an integer, then the absolute value of n is greater than 0. Solution: Since 0 is an integer, we let n = 0. Now |n| = |0| = 0 > n. We have found a counter example. Thus, the statement “If n is an integer, then the absolute value of n is greater than 0 is a false statement. 2. DEDUCTIVE REASONING – It is the process by which one makes conclusion based on previously accepted general assumptions, procedures and principles. Example: PREMISE – There are 23 books on the bookshelf and 16 on the lower shelf. There are no books on the bookshelf. CONCLUSION – therefore, there are 39 books in the bookshelf. POLYA’S PROBLEM-SOLVING STRATEGY POLYA’S 4 STEP PROBLEM-SOLVING STRATEGY 1. Understand the problem – you must have clear understanding of the problem and have ready answers to questions. 2. Devise a plan – some of procedures include in making a list of known information, making a list of information that is needed, sketching a diagram, making an organized list that shows all possibilities, making a table or chart, working backwards, trying to solve a similar but simpler problem. 3. Carry out the plan – you need to work carefully and keep an accurate and neat record of all you attempts. 4. Review the solution Example 1. Katrina sells eggs by piece. On the first day, she sold a half more than half the number of eggs for sale. On the second day, she sold a half more than half the remaining number of eggs on the first day. On the third day, she again sold a half more than a half the remaining number of eggs from the second day. Only a dozen eggs were left for the fourth day. How many eggs did she have originally? Understand the problem. We need to determine the number of eggs before Katrina started selling them Devise a plan. Algebraic solution is okay but working backwards is more preferable because we knew already the end result. Carry out the plan. Since only 12 eggs were left, equivalent to half less than half the number before she started selling eggs on the third day. It follows that half the number is 12.5 which means that there were 25 eggs left on the second day. There were 25.5 = 51 eggs just before she started selling eggs on the second day, and so before she started selling eggs on the first day, there were originally 51.5 x 2 = 103 eggs. 6 Review the solution. To check our solution, we start 103 eggs and proceed through each day of sale. Day 1: 103 – (51.5 + 0.5) = 103 – 52 = 51 Day 2: 51 – (25.5 + 0.5) = 51 – 26 = 25 Day 3: 25 – (12.5 + 0.5) = 25 – 13 = 12 2. A basketball team won two out of their last four games. In how many different orders could they have two wins and two losses in four games? WWLL WLLW LWWL LWLW LLWW WLWL 3. How many rectangles do we have? 18 rectangles LESSON 4 DATA MANAGEMENT DIVISIONS OF STATISTICS 1. DESCRIPTIVE – Statistical procedure concerned with describing the characteristics and properties of a group of persons, places or things that was based on verifiable facts. Example: How many students are interested to take statistics online? A basketball player wants to find his average shots for the past 10 games. 2. INFERENTIAL – statistical procedure used to draw inferences for the population on the basis of information obtained from the sample using the technique of descriptive statistics. Example: Is there significant difference in the academic performance of male and female students in statistics? A politician wants to estimate his chance of winning in the upcoming senatorial election. DATA COLLECTION AND PRESENTATION OF STATISTICAL DATA METHODS FOR COLLECTING DATA 1. DIRECT OR INTERVIEW METHOD – person to person exchange of data from interviewer to interviewee. 2. INDIRECT OR QUESTIONNAIRE METHOD – responses are written and given more time to answer. Questionnaires are given to the respondents. 3. REGISTRATION METHOD – The respondents provide information in the compliance with certain laws, policies, rules, regulations, decrees, or standard practices. 7 4. EXPERIMENTAL METHOD – the researcher wants to control the factors affecting the variable being studied to find out cause and effect relationships. 5. OBSERVATION METHOD – utilized to gather data regarding attitudes, behavior and cultural pattern of the samples under investigation. WAYS IN PRESENTING DATA 1. TEXTUAL PRESENTATIONS – data are presented in paragraphs or sentences. Example: Nominally, the peso improved by 1.4 percent as of April 14, 2003 compared to its level in 2002, followed by the Thai baht which gained 0.86 percent; Indonesian rupiah, 0.68 percent; and Taiwan dollar, 0.2 percent. Other currencies, on the other hand, depreciated during the same period. The Singapore dollar fell 2.33 percent. The South Korean won slid 2.14 percent while the Japanese yen dropped 0.61 percent. 2. TABULAR PRESENTATION – it use rows and columns and data are presented systematically and ordered. Example: 3. GRAPHICAL PRESENTATION a. SCATTER GRAPH – graph used to present measurements or values that are thought tobe related. b. LINE CHART/GRAPH – useful for showing trends over a period of time. 8 c. PIE CHART/GRAPH – circular graph that are useful in showing how a total quality is distributed among a group of categories. d. COLUMN AND BAR GRAPH – it is applicable only for grouped data. Used for discrete, grouped data of ordinal or nominal scale. MEASURES OF CENTRAL TENDENCY - It is a numerical descriptive measure in which indicate or locate the center of a distribution of a set of data. 1. MEAN or ARITHMETIC MEAN – commonly known as average. It is represented by EXAMPLE: The numbers of students at six different classrooms are 25, 27, 29, 24, 35 and 28. Find the mean. M = Tx/n M = 25 + 27+ 29+ 24+ 35 +28/6 M = 168/6 M = 28 2. MEDIAN – the middle position of arranged values from lowest to highest. It is the middlemost score. EXAMPLE 1: Given 3, 4, 7, 8, 10, 12 and 14 = 8 is the median because it is in the middle term. EXAMPLE 2: Given the following scores: 80, 81, 82, 83, 84, and 85, compute for the median. 9 80, 81, 82, 83, 84, 85 = 82 and 83 is the middlemost so we will get the average of this. Md = 82 + 83 = 165 Md = 165 ÷ 2 = 82.5 therefore, 82.5 is the median EXAMPLE 3: Solve for the median of the following raw scores: 6,7,8,9,9,10,12,14,15 Md = 𝟗 + 𝟗 + 𝟏𝟎 𝟑 Md = 9.33 therefore, 9.33 is the median 3. MODE – most frequently observed value that occurs. EXAMPLE: Find the mode of the ff. data: 63, 100, 84, 88, 73, 86, 97,95, 97 Arranging the values from least to greatest makes it easier to find the mode 63, 73, 84, 86, 88, 95, 97, 97, 100 Find the number that appears more or most frequently The value 97 appears twice. All other numbers appear just once. Therefore, 97 is the MODE A set of data can have: No mode One mode More than one mode 9, 11, 16, 6, 7, 17, 18 – NO MODE 9, 11, 16, 8, 16 – HAS ONE MODE 18, 7, 10, 7, 18 – MORE THAN ONE MODE 4. WEIGHTED MEAN – is a mean calculated by giving values in a data set more influence according to some attribute of the data. Mw = 𝐓(𝐰𝐟) Where: 𝐓𝐟 T(wf) = total or sum of weight times frequency Tf = N = total or sum of the frequencies EXAMPLE: Ely’s wants to determine if he passed the subject. Given the following data, did Ely pass the subject? Grading system Quizzes Recitation Assignment Seatwork Term exam TOTAL Ely’s grade : = = Weighted percentage 25% = .25 15% = .15 10% = .10 20% = .2 30% = .3 100% Ely’s score 74 90 85 65 73 (74 x .𝟐𝟓) + (90 x .𝟏𝟓) + (85 x .𝟏𝟎) + (65 x .𝟐) + (73 x .𝟑) 𝟏𝟎𝟎% 𝟏𝟖.𝟓 + 𝟏𝟑.𝟓 + 𝟖.𝟓 + 𝟏𝟑 + 𝟐𝟏.𝟓 = 75.4% 𝟏𝟎𝟎% Therefore, Ely passed the subject with this grade 10