A DETAILED LESSON PLAN IN MATHEMATICS FOR GRADE-FOURI. OBJECTIVES At the end of a 45-minute period, the grade four pupils will be able to: 1. Add and subtract fractions with the same denominators, 2. Add and subtract fractions with dissimilar denominators, 3. Add and subtract mixed numbers with similar denominators, and 4. Add and subtract mixed numbers with dissimilar denominators with 75% proficiency level.II. SUBJECT MATTER ADDING AND SUBTRACTING OF FRACTIONS A. References Liking Mathematics in the Grade School: Textbook in Mathematics for Grade-Four by Prepotente et.al. 21st Century Mathematics (6) by Villame et.al. B. Materials Power point presentation, visual aids C. Ideas To add/subtract fractions with similar denominators, we add/subtract the numerator and write the sum/difference over the same denominator. To add/subtract fractions with dissimilar denominators, first find the smallest equivalent fractions by using the least common multiple (LCD) to rename the dissimilar fractions into similar fractions and then proceed as in adding/subtracting fractions with the same denominator. To add/subtract mixed numbers with similar denominators, we add/subtract the whole numbers, then the numerators and retain the denominator. To add/subtract mixed numbers with dissimilar denominators, change dissimilar fractions to similar fractions. Add/subtract the whole numbers, and then the numerators and copy the denominator. D. Processes Identifying, adding, subtracting E. Value Small parts are necessary to make-up a whole.III. PROCEDURE A. Pre-assessment 1.Prayer 2.Checking of attendance
3.Review of the past lessonB. Motivation A song about mathemeticsC. Lesson proper Teacher Activity Pupil Activity Class, do you love to eat chocolates? Yes Ma’am Who wants to eat a chocolate? We’d love to, Ma’am. I have here a bar of chocolate and I am going to divide it equally into four parts. (Slice). So I have now 4 slices or 4/4 of chocolate. (Give the 2/4 of the apple to two pupils, 1/4 each). So I have given Mario ¼ of the chocolate and another ¼ to Rowena. How much chocolate have I given all in all and how 2/4 given much is left? 2/4 left Yes Very Good! I sliced the chocolate into fourequal parts so we get 4/4 or 1 of course and I gave Mario and Rowena ¼ each of the chocolate. So ¼ + ¼ , we get 2/4 or ½ and the parts that is left for me is also 2/4 0r ½ . If we are going to add the parts of apple that I have given to Mario and Rowena and the parts left for me, how much will it be all in all? 4/4 or 1 Now class, do you have any idea of what will be our topic for today? Adding and subtract- ing of fraction Exactly class. Today, we will be discussing how to add and subtract fractions. And I want you to meet the following objectives which are to: add and subtract fractions with the same denominators, add and subtract
fractions with dissimilar denominators,add and subtract mixed numbers withsimilar denominators, and add andsubtract mixed numbers with dissimilardenominators with 75% proficiencylevel. Can I expect that from you? Sure Ma’am.So we have here different rules inadding and subtracting of fractions.Take note that I am going to give youa quiz after this so you better bearwith me class, listen carefully as I amgoing to present and discuss each ruleone after the other.To add fractions with similardenominators,we simply add thenumerators andwrite the sum overthe same denominator.Dulce ate ⅖ of the cake in the morningand ⅕ in the afternoon. How much cakewas eaten by her?What is asked in the problem? The amount of cake eaten by Dulce.What are given? 2/5 cake in the morning and 1/5 in the afternoon.So we are going to add the givenfractions to answer what is asked inthe problem. As what is stated in therule, we simply add the numeratorsand write the sum over the samedenominator in adding of similarfractions. So we simply add 2 and 1which is equal to 3 and write it overthe same denominator which is 5.And the answer is 3/5.
Did you get it? Yes Ma’am.So let’s proceed.To subtract fractions with similardenominators, we simply subtractthe numerators and write the differenceover the same denominator.This is somewhat similar as in addingof fractions with similar denominators.The only difference is we are going tosubtract the numerators instead of addingA water tank was ⅞ full of water. After aday of use, it was ⅜ full. How much waterwas used during the day?What is asked? The amount of water that was used during the day.What are given? 7/8 full of water and 3/8 full after a day of use.To find the amount of water that wasused during the day, we are going tosubtract 3/8 from 7/8. So simply subtractthe numerators 7-3 is equal to 4 and writeit over the same denominator which is 8and then we get 5/8.To add fractions with dissimilardenominators, rename thedissimilar fractions into similarfractions by finding the (LCD) and thenproceed as in adding fractions with thesame denominator.Mother used ⅗ liter of cooking oil last monthand⅔ liter this month. How much did sheuse in two months?What is asked? The amount of cooking oil
mother used in two months.What are given? 3/5 liter of cooking oil last month and 2/3 liter this month.How do we add 3/5 and 2/3?Examine their denominators. Do theyhave the same or what? Different/dissimilarObviously! So the first we need to findThe LCD or (Least Common Denominator).What is the LCD of 5 and 3? 15Aha! And we are going to use 15 torename these dissimilar fractions intosimilar fractions. And then we get 9/15and 10/15 so we can now add thesesimilar fractions to get the answer whichis 19/15 or 1 4/15.To subtract fractions with dissimilardenominators, rename the dissimilarfractions into similar fractions by findingthe (LCD) and then proceed as insubtracting fractions with the samedenominator.Aling Dionisia, a stuffed-toy maker, uses 5/9bag of stuff for a dog and 4/6 bag of stuff fora cat. How much more stuff does she usefor a dog than for a cat.What is asked? The amount of stuff she use for a dog than for a cat.What are given? 4/6 bag of stuff for dog and 5/9 bag of stuff for a cat.Like adding of fractions withdissimilar denominators, we needTo find the LCD in order to rename
these fractions into similar fractionsallowing us to proceed in subtraction.What is the LCD of 6 and 9? 18So the fractions involved are now12/18 and 10/18. And to answer what isasked in the problem we are going tosubtract 10/18 from 12/18 and we get2/18 or 1/9..To add mixed numbers with similardenominators, we add the wholenumbers,then the numerators and retainthe denominator.What do you mean by mixed numbers? A mixed number is composed of a whole number and a fraction.Yes, exactly! We have discussed that already.Jebs and Brion helped in the “OperationLinis” on Saturday and Sunday. Johnmowed 3⅓ of the lawn and Bob mowed4⅓ of it .What part of the lawn did the twoboys mow together?What is asked? The part of the lawn the two boys mow together.What are given? John mowed 3⅓ of the lawn and Bob mowed 4⅓ of it.3⅓ and 4⅓ are examples of mixednumbers with similar denominatorsof which we can just add directlywithout the need of finding an LCD.
We automatically add the whole numbers-3+4=7 and then the numerators- 1+1=2and write it over the same denominator- 3.The part of the lawn the two boys mowedtogether is 7 2/3.To subtract mixed numbers with similardenominators, we subtract the wholenumbers, then the numerators and retainthe denominator.A vendor sold 316/7 kilograms of mangoeson Monday and 26 5/7 kilograms on Tuesday.How much more kilograms of mangoes didshe sell on Monday than on Tuesday?What is asked? The amount of mangoes in kls that she sell more on Monday than on Tuesday.What are given? 31 6/7kls of mangoes on Monday and 26 5/7 kls on Tuesday.As stated in the rule we are going tosubtract first the whole numbers-31-26=5, and then the numerators-6-5=1 and write it over the samedenominator 7. And we get the answerwhich is 5 1/7.To add mixed numbers with dissimilardenominators, change dissimilarfractions to similar fractions. Add thewhole numbers, and then the numerators,and copy the denominator.Vener and Edmund opened a vegetablestand in a supermarket. On opening day,
they sold 4 5/8 bushels of corn andsold 3 4/6 bushels on the following day.How much corn was sold in two days?What is asked? The amount of corn that was sold for two days.What are given? On opening day, they sold 4 5/8 bushels of corn and sold 3 4/6 bushels on the following dayHow are we going to change dissimilarfractions into similar fractions? find the LCDPrecisely! And what is the LCD of8 and 6? 48Through obtaining the LCD of dissimilarfractions, we can derived its similarfractions and then perform the indicatedoperation. 4 5/8 and 3 4/6 = 4 30/8 and 3 24/8.When added, 4+3=7(whole numbers) and 54/8(similar fractions) we get 7 54/8.To subtract mixed numbers withdissimilar denominators, changedissimilar fractions to similar fractions.Subtract the whole numbers, and then thenumerators, and copy the denominator.Mang Tony is a candle maker. He had 5 3/4disks of wax. He used 4 2/5 of them.How much wax does he have left?What is asked? The amount of wax he have left.What are given? He had 5 2/5 disks of wax and he used 4 3/4 of them.
What is the LCD of 4 and 5? 20 Through the use of LCD we can now derived similar fractions where we can apply operations directly. In this case the fractions that we derived are 5 15/20 and 4 8/20. Subtract the whole numbers- 5-4=1 and then the numerators- 15-8=7 and write it over the same denominator 20. The answer is 1 7/20. Deductive MethodIV. EVALUATION Direction: Solve each problem. 1. Julie bought ½ meter of red ramie cloth for her table napkins and 3/6 white ramie cloth for placemats. How many meters of cloth did she buy? 2. Mrs. Robles baked 1⅔ dozen cookies. She brought ¾ dozen to school for her friends. How many dozen of cookies were left?V. ASSIGNMENT Direction: Perform the indicated operation. a. 1 2/5+3/5 b. 2 ¼ - 2/4 c. 1-6/6