Topics with more concepts or lengthy notes are broken up into 2-3 weeks so it would not be too overwhelming for the students to learn all the concepts at once. Primary 4 Chapter 5 Fractions Notes (I) Mixed Numbers A mixed number is made up of a whole number and a fraction. A mixed number is obtained when a whole number is added to a fraction. Key words are in bold to emphasise their importance. Worked Example 1 Noel ate 1 apple pie. Ken ate 1 4 of an apple pie. How much apple pie did they eat altogether? Speech bubbles are placed at the side from time to time to serve as a reminder. Solution: 1 1 is a mixed number where 4 1 is the whole number and 1 4 is the fraction. Whole Number 1+ 1 1 4 Fraction 1 1 =1 4 4 They ate 1 1 apple pies altogether. 4 -1- P4 | Chapter 5 Fractions | Notes (I) © JustEdu Holdings Pte Ltd Practice questions to further enhance student’s understanding of new topic. Write down the mixed number represented for Questions 1 and 2. 1) 1 whole 1+ 3 4 = __________ 2+ 1 6 = __________ 3 quarters 2) 1 whole 1 whole 1 sixth 3) Express the mixed number in its simplest form. To express in its simplest form, divide both the numerator and denominator by the same number until they cannot be divided further. E.g. 3 4 ÷4 = 3 1 8 ÷4 2 ________ wholes ________ parts = 4 4) 6 =4 Express the mixed number in its simplest form. The first one has been done for you. (a) 1 3 6 =1 (c) 6 3 9 =6 1 2 -2- (b) 2 6 8 (d) 3 8 12 =2 =3 P4 | Chapter 5 Fractions | Notes (I) © JustEdu Holdings Pte Ltd Improper Fractions At a cake shop, cakes are cut into 6 equal pieces. 1 6 = 1 sixth 5 6 = 5 sixths 6 6 = 6 sixths = 1 whole 7 6 = 7 sixths = Visuals help our students to grasp the concept quickly. 1 6 When a numerator of a fraction is equal to or greater than its denominator, we get an improper fraction. Hence 6 and 7 are improper fractions. 6 6 Can you find other improper fractions on the number line below? 1 0 1 6 2 6 3 6 4 6 5 6 6 6 11 12 13 14 7 6 8 6 9 6 10 6 6 6 6 6 15 6 11 6 2 12 6 The value of an improper fraction is equal or greater than 1. It can be expressed as a whole number or a mixed number. -3- P4 | Chapter 5 Fractions | Notes (I) © JustEdu Holdings Pte Ltd 5) 2 3 How many thirds are there in 2 ? 2 2 3 = 3 = __________ thirds 2 3 There are __________ thirds in 2 . As much as we would love to show you everything, we cannot be showing you the best. Do drop by any JustEdu centre to view the full set! -4- P4 | Chapter 5 Fractions | Notes (I) © JustEdu Holdings Pte Ltd Sub-titles are used to identify the different learning objectives of the topic. Convert Improper Fractions to Mixed Numbers Worked Example 2 Express 11 9 as a mixed number. Solution: Method 1: 11 9 = 11 ninths We separate 11 ninths into 9 ninths + 2 ninths because we know 9 = 1! 9 = 9 ninths + 2 ninths = 9 9 + =1+ =1 2 9 2 9 2 9 -5- P4 | Chapter 5 Fractions | Notes (I) © JustEdu Holdings Pte Ltd Alternative method is presented to cater to different learning styles and abilities of students. Method 2: 11 9 We can think of this line as a division symbol, 11 ÷ 1 9 11 – 9 2 9= 1R2 = 1 2 9 ÷ Remainder Denominator Quotient Hence, 11) 11 9 =1 Express 2 9 32 7 as a mixed number using both Method 1 and Method 2. Method 1: 32 7 = sevenths = sevenths + = + = + Note: 7 =1 7 14 =2 7 21 =3 7 28 =4 7 sevenths = Method 2: 32 ÷ 7 = R 7 32 – 32 7 = -6- P4 | Chapter 5 Fractions | Notes (I) © JustEdu Holdings Pte Ltd 12) Express 16 10 as a mixed number in its simplest form using both Method 1 and Method 2. Method 1: 16 10 Note: = tenths = tenths + = + = + 10 10 =1 tenths = Method 2: 16 ÷ 10 = 16 10 R = 10 1 6 – = -7- P4 | Chapter 5 Fractions | Notes (I) © JustEdu Holdings Pte Ltd Convert Mixed Numbers to Improper Fractions Worked Example 3 Express 2 5 6 as an improper fraction. Solution: Alternative method is presented to cater to different learning styles and abilities of students. Method 1: 2 5 6 =2+ = 12 6 = 17 6 5 6 5 6 + Note: 1= 6 2= 6 12 6 Method 2: 1 2 5 6 2 2 multiply these 3 5 6 Then add this to the product 2×6 + 5 2×6+ 5 = 17 This is your new numerator. 2 65 17 = 6 -8- P4 | Chapter 5 Fractions | Notes (I) © JustEdu Holdings Pte Ltd Our notes are complemented with 2-3 sets of comprehensive practice papers each week. This is to ensure our students are able to apply the concepts into different types of Mathematical sums. Primary 4 Chapter 5 Fractions Practice 1 1) Shade all the boxes with mixed numbers to help Mew Mew find the way to its dinner. 3 1 8 4 15 8 2) 9 2 5 43 12 2 3 7 2 4 9 10 1 9 5 37 9 1 7 4 7 3 11 1 1 4 10 10 Write the mixed number for each of the following. (a) 1 whole and 1 quarter is __________. (b) 2 wholes and 5 eighths is __________ . -1- P4 | Chapter 5 Fractions | Practice 1 © JustEdu Holdings Pte Ltd 3) 4) Shade the following to show the given number of parts. (a) 2 2 3 (b) 3 3 8 Fill in the boxes on the number line with the following mixed numbers. 23 5) 2 1 8 2 2 37 4 8 (c) (b) (a) 2 23 31 8 2 8 2 4 8 2 5 8 2 7 8 3 1 38 3 2 38 38 (d) 3 5 8 6 4 38 Fill in the boxes on the number line with mixed numbers in its simplest form. (a) 0 1 2 2 1 3 (b) 4 5 42 5 -2- P4 | Chapter 5 Fractions | Practice 1 © JustEdu Holdings Pte Ltd 6) Write mixed numbers for the following. Express your answers in its simplest form. (a) Find the volume of water in each container. 2l 2l 1l 1l __________ (b) l __________l Find the total mass of the papayas. The papayas have a total mass of __________kg. -3- P4 | Chapter 5 Fractions | Practice 1 © JustEdu Holdings Pte Ltd Do drop by our centre to view the full set of materials. -4- P4 | Chapter 5 Fractions | Practice 1 © JustEdu Holdings Pte Ltd Visuals help our students to grasp the concept quickly. 7) Study the diagrams and write an improper fraction for each of the following. (a) 11 quarters = __________ (b) 17 fifths = __________ -5- P4 | Chapter 5 Fractions | Practice 1 © JustEdu Holdings Pte Ltd 8) 9) Write an improper fraction for each of following. (a) 8 sevenths = (b) 7 fifths = (c) 11 eighths = (d) 13 thirds = Write each of the following as a mixed number and an improper fraction. (a) Mixed number → Improper fraction → Mixed number → Improper fraction → (b) Do drop by our centre to view the full set of materials. -6- P4 | Chapter 5 Fractions | Practice 1 © JustEdu Holdings Pte Ltd 10) Fill in the missing fractions in each box. Express your answers in its simplest form. (a) 2 1 0 (b) 2 1 11) Write each mixed number as an improper fraction. (a) 1 = __________ quarters 3 4 = __________ quarters 3 4 1 1 = __________ quarters 1 3 4 = Do drop by our centre to view the full set of materials. -7- P4 | Chapter 5 Fractions | Practice 1 © JustEdu Holdings Pte Ltd 12) Write down the improper fractions for the shaded parts. (a) 1 whole 1 5 6 = 5 6 There are __________ sixths in 1 . (b) 1 whole 3 4 9 = 4 9 There are __________ ninths in 3 . -8- P4 | Chapter 5 Fractions | Practice 1 © JustEdu Holdings Pte Ltd Topics with more concepts or lengthy notes are broken up into 2-3 weeks so it would not be too overwhelming for the students to learn all the concepts at once. Primary 4 Chapter 5 Fractions Practice 8 Worked Example 1 Electrician Adam had 14 m of wire. 2 7 of it was damaged and cut off. 1 He used another 6 4 m of wire for the living room. (a) What was the length of wire that was damaged? (b) What was the length of remaining wire? Speech bubble is placed by the side from time to time to serve as a reminder. Look out for the units. Worked examples are used to guide students Solution: on the answering of the question. It is also useful for students to refer to 2 × 14 m = 4 m (a) when revising. 7 Notice that 2 has no unit. 7 2 7 of the wire ≠ 2 m of the wire 7 Therefore, you have to find its length. The length of the wire that was damaged was 4 m. (b) 14 m – 4 m – 6 1 4 m=4m– =3 4 4 m– =3 3 4 m 1 4 1 4 m m The length of the remaining wire was 3 -1- 3 4 m. P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd Students are drilled and different Solve the following problem sums. All essential workings must be shownexposed clearly.toAnswers aretypes to of problem sums to prepare be given in the correct units and in their simplest form. them for examination. 1) Amelia bought 16 kg of apples. She used 5 8 of it to bake apple pies and gave 1 4 9 kg of it to her neighbours. What was the mass of the apples she had left? Ans:__________ 2) Gloria prepared 20 l of fruit punch for a party. After a few hours, the guests finished Gloria prepared another 4 1 2 3 5 of the fruit punch. l of fruit punch. How much fruit punch was there now? Ans:__________ -2- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd 3) The distance between Town G and Town H is 240 km. Mr Koh drove from Town G towards Town H in the morning and he completed 5 12 of the distance. Mrs Koh took over the driving from Mr Koh and drove 85 km in the afternoon. What was the distance left for them to reach Town H? Different worked examples are introduced in the practice papers to guide students on how to answer the different type of questions. It is also useful for students to refer to when in doubt. Worked Example 2 Tina had 60 eggs. She broke 6 eggs. 1 2 She then gave (a) (b) Ans:__________ of the remaining eggs to her neighbour. What fraction of the eggs did Tina break? How many eggs did she give to her neighbour? Solution: (a) 6 60 = 1 10 1 10 Tina broke (b) Alternatively, 1 of the remaining = of the eggs. 2 1 2 × 54 60 – 6 = 54 (Remaining eggs) 54 6 ? 54 ÷ 2 = 27 Tina gave 27 eggs to her neighbour. -3- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd 4) Fiona has 60 notepads. She lost 10 of them. She gave away 2 5 of her remaining notepads. How many notepads did she give away? Ans:__________ 5) There were 100 people in a cinema. Halfway through the movie, 16 people left. 5 12 of the remaining people were women. How many women remained in the cinema? Ans:__________ -4- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd Do drop by our centre to view the full set of materials. -5- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd Worked Example 3 The total cost of a shirt and a pair of pants is $75. The cost of the shirt is 2 3 that of the pair of pants. How much does the shirt cost? Solution: Pants $75 Shirt 3 units + 2 units = 5 units 5 units → $75 1 unit → $75 ÷ 5 = $15 2 units → $15 × 2 = $30 The shirt costs $30. Look out !!! 2 units The cost of the shirt is that of the pair of pants. 3 units This would help you to draw the model. -6- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd 7) The total mass of 2 girls is 88 kg. If the mass of one girl is 3 5 of the other, what is the mass of the heavier girl? Ans:__________ Do drop by our centre to view the full set of materials. -7- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd -8- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd 8) Ans:__________ Taylor has a bouquet of roses. The number of blue roses is 1 3 the number of pink roses. The number of pink roses is 1 2 the number of red roses. What fraction of the bouquet are red roses? Ans:__________ 9) Lindsay has 3 containers of water, A, B and C. 3 Container A has 7 as much water as Container B. 1 Container C has 3 as much water as Container A. If the total volume of water is 22 l, how many litres of water are there in Container A? Tip: Draw a model. Ans:__________ -9- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd *10) 2 5 4 of Christina’s salary is 7 of Brittany’s salary. Christina earns $900 more than Brittany. What is their total salary? Students are further exposed to more challenging questions in their Practice. These questions are often differentiated by the asterisk* next to question’s number. Ans:__________ -10- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd * 11) The volume of water in Tank X was 1 5 the volume of water in Tank Y. After 23 ml of water was removed from Tank X and 1845 ml of water Do drop by our centre to view the full set of materials. -11- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd * 12) Gordon has two number cards. The first card contains a whole number that is smaller than 15. The second card contains a proper fraction. Do drop by our centre to view the full set of materials. -12- P4 | Chapter 5 Fractions | Practice 8 © JustEdu Holdings Pte Ltd
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