TERM: 2^{nd} Term
WEEK: 8
CLASS: Primary 2
AGE: 7 years
DURATION: 5 periods of 40 minutes each
DATE:
SUBJECT: Mathematics
TOPIC: Mass
SPECIFIC OBJECTIVES: At the end of the lesson, the pupils should be able to
INSTRUCTIONAL TECHNIQUES: Explanation, question and answer, demonstration, practical
INSTRUCTIONAL MATERIALS: Balance scale, objects to compare mass (e.g. board duster, box of crayons, etc.),bathroom scale, packaged items to compare and add given masses, (500 g bag of rice, 1 kg bag of rice, tea, mielie meal, etc.), Pictures of/products with a mass of 250 g, 500 g, 1 kg and 2 kg, bathroom scale, objects with a mass of 1 kg, 5 kg, 10 kg and 20 kg.
PERIOD 1: Assessment
PRESENTATION  TEACHER’S ACTIVITY  PUPIL’S ACTIVITY  
STEP 1 ORAL ASSESSMENTS  The teacher asks questions on mental maths treated so far  Pupils respond and participate  
STEP 2 DISCUSSION  The teacher discusses all the methods used by some learners in the oral assessments(some of the questions are solved on the board by the learners) and addresses any misconceptions that may have risen  Pupils pay attention and participate  
STEP 3 WRITTEN ASSESSMENTS  1 Circle the container that can hold more water. 2 This bottle has 1 teaspoon of water in it. How many teaspoons of water are there in the following bottle? 3 Write these measurements from smallest to biggest: 4 l, 2 l, 3 l, 1 l and 5 l.
4 Draw 3 containers below to show the difference in capacity.
5 Solve the problems: a Mom buys 2 litres of orange juice on Monday. She buys another 4 l on Tuesday. How many litres did she buy altogether?
b Bisi has 5 l of water. Joshua has 7 l. How many more litres does Joshua have?  Pupils attempt their class work  
STEP 4 SUMMARY  The teacher marks the written assessments, corrects were necessary and commends the pupils 

PERIOD 2: Standard units of mass
PRESENTATION  TEACHER’S ACTIVITY  PUPIL’S ACTIVITY 
STEP 1 MENTAL MATHS  The teacher begins the lesson with some mental calculations which is more 1 51 or 15? 2 12 or 21? 3 100 or 10? 4 75 or 57? 5 30 or 50? 6 78 or 87? 7 98 or 89? 8 55 or 45? 9 25 or 52? 10 56 or 65?  Pupils respond and participate 
STEP 2 CONCEPT DEVELOPMENT  The teacher • Using a balance scale, compare the mass of an assortment of objects to see which one is heavier/lighter. • Puts one object on either side of the balance scale. • Compares their masses based on what you see: Which is heavier? (The heavier object will hang lower than the lighter object.) Which is lighter? (The lighter object will hang higher than the heavier object.) • Uses objects such as a board duster, a box of crayons and a school lunch box together. CLASS ACTIVITY The teacher In this activity you start to work with standard units of measurement (kg). • Asks the class to explain the difference between light and heavy objects. They should use pairs of objects to give their explanations. I am heavy but my book is light. The teacher’s desk is heavy but her chair is light. • Puts the 500 g and 1 kg of rice in front of the learners so that they are clearly visible to all. Discusses the mass of each. One is 500 g and the other is 1 kg. • Asks: If I have 2x 500 g bags of rice how many grams do I have? (1000 g) • Says: 1000 g is the same as 1 kg. Uses the bags of rice to show this. • Places the 10 kg mealie meal, 5 kg sugar and 1 kg rice in front of the learners (or any other products of the same mass). • Asks: Which of the packages is heavy? Which is light? (Discuss.) • Uses any pair of items in a sentence with the word heavier/lighter. • Discusses kilograms as a unit of measurement. (It is a standard unit.)
ACTIVITY II Do this activity allowing individuals from each group to find their own mass while the rest of the class starts the classwork activity. Calls the learners to the front of the class, one group at a time, so that they all get the chance to find their mass using the scale. • Uses bathroom scale. Get each learner to come up to the front and measure their mass. • Asks: What is your mass in kilograms? (Learners answer in turns.) • You don’t have to record their masses on the board. This is not a comparison exercise but rather one to establish understanding of mass and how to read your mass on a scale.  Pupils pay attention and participate 
STEP 3 CLASSWORK  1 Draw the following products with a different mass: a 2 kg rice, 5 kg potatoes, 10 kg mealie meal, 1 kg sugar. b Write down the mass of each product.
2 Use the pictures from Question 1 to complete the following: a Mom bought mealie meal and rice. What is the total mass of her products? b I bought some rice, sugar and potatoes. What is the total mass of my products? c Dad bought sugar and mealie meal. What is the total mass of his products? d My sister bought mealie meal, sugar and rice. What is the total mass of her products?  Pupils attempt their class work 
STEP 4 HOMEWORK  Note: The answers here will vary according to the products the learners find. Take some time to discuss the learners’ work and check their addition.
1 Find and draw 3 products with a different mass in your kitchen at home, e.g. flour, sugar, mealie meal. Write the mass next to the picture.
2 Complete these sentences, using the products from your kitchen. a Mom bought _______ and _______. The total mass is _______ kg. b Dad bought ________ and _______. The total mass is ______kg. c I bought _______ , _______ and _______. The total mass is _____kg.
 The pupils writes it in their homework book 
STEP 5 SUMMARY  The teacher summarizes by reminding the pupils that in this lesson we have learnt to measure the mass of objects using kilograms.
She marks their class works, makes corrections where necessary and commends them positively 

PERIOD 2: Estimation of mass
PRESENTATION  TEACHER’S ACTIVITY  PUPIL’S ACTIVITY 
STEP 1 MENTAL MATHS  The teacher begins the lesson with some mental calculations Give the number(s) between 1 56 and 58 2 91 and 95 3 25 and 27 4 40 and 43 5 35 and 38 6 12 and 14 7 50 and 53 8 98 and 100 9 89 and 91 10 24 and 27  Pupils respond and participate 
STEP 2 CONCEPT DEVELOPMENT  The teacher • Shows learners products/pictures with a mass of 250 g, 500 g, 1 kg and 2 kg. • Asks them the following questions: Which product has a mass of 1 kg? Which product has a mass of less than 1 kg? Which product has a mass of more than 1 kg? Is the remaining product lighter or heavier than 1 kg? (Learners should respond using the examples shown to the class in the pictures you have collected. Answers will depend on the pictures you have brought to class.)
ACTIVITY II The teacher When you do this activity make sure that you show the learners how to read mass correctly using scale markings. Draw a simple scale on the board to assist you when you explain how to read from a scale. For example: (Draw the scale arm to show different readings using the markers.) • Use a bathroom scale to find the mass of the following: An object with a mass of 1 kg. An object with a mass of 5 kg. An object with a mass of 10 kg. An object with a mass of 20 kg. • Asks questions like (answers will vary): Which object has the greatest mass? Which object has the lowest mass? Which object is heavier/lighter? (Of two objects shown together.) Which object has a mass of more than 5 kg/less than 10 kg? • When you have finished this activity the learners will do the classwork activity. • Draws a balance scale on the board to remind learners how to interpret a drawing of a balance scale. • Reminds the class: In the scale shown, the object on the right hand side is heavier because the scale is tipping down to the right. • The masses shown in the two balances are 1 kg on the left and 2 kg on the right. This scale would tip towards the heaver object, which is the 2 kg bag of soap. The balance scale shown here is true.  Pupils pay attention and participate 
STEP 3 CLASSWORK  1 Look at the pictures of balance scales. Circle true or false. 2 Draw the arms on the kitchen scales to show the mass of these products: (Learners must draw the arms in the correct place.)  Pupils attempt their class work 
STEP 4 HOMEWORK  1 Draw a scale balance with a heavier object on the right hand side. 2 Draw a scale balance with a lighter object on the left hand side. 3 What can you say about the two drawings that you drew?
 The pupils writes it in their homework book 
STEP 5 SUMMARY  The teacher summarizes by reminding the pupils that in today’s lesson we have learnt to estimate and read the mass of objects using kilograms.
She marks their class works, makes corrections where necessary and commends them positively 

PERIOD 4: Mass: addition and subtraction problems
PRESENTATION  TEACHER’S ACTIVITY  PUPIL’S ACTIVITY 
STEP 1 MENTAL MATHS  The teacher begins the lesson with some mental calculations Put the largest number first 1 54, 55, 56 2 71, 70, 69 3 53, 55, 54 4 61, 62, 63 5 23, 21, 22
Put the smallest number first 6 65, 63, 64 7 32, 30, 31 8 12, 16, 14 9 38, 40, 36 10 50, 51, 49  Pupils respond and participate 
STEP 2 CONCEPT DEVELOPMENT  The teacher • Before the lesson draw pictures of products and write the mass under each product/ place products with the following masses on a desk at the front of the class: a 1 kg b 5 kg c 2 kg d 10 kg • Asks the learners to read the mass of each product. • Discusses with the learners which object is the heaviest/lightest. • Shows the learners the objects with a mass of 2 kg and 5 kg. • Asks: How many kilograms would I have if I added the mass of these 2 objects together? (2 kg + 5 kg = 7 kg). • Selects different containers and ask learners different addition problems. • Shows the learners the objects with a mass of 10 kg and 2 kg. • Asks: How many kilograms will I have if I subtract a mass of 2 kg from a mass of 10 kg? (10 kg – 2 kg = 8 kg). • Selects different containers and ask the learners different subtraction problems.
CLASS ACTIVITY The teacher • Using the 500 g, 1 kg, 2 kg, 5 kg and 10 kg objects. • Shows the learners the 2 kg and 1 kg object. • Asks: How many 1 kg objects do you need to make 2 kg? (2) • Repeats this type of question using 1 kg and 2 kg and 5 kg and 10 kg objects. • Shows the learners the objects with a mass of 500 g and 1 kg. • Asks: How many 500 grams objects do I need to make a mass of 1 kg? (2) • Discusses that 1000 g = 1 kg.  Pupils pay attention and participate 
STEP 3 CLASSWORK  1 Draw five objects, each with a different mass. Write the mass of each object under the picture.
2 What is the total mass of the objects whose pictures you drew? ______ kg.
3 Joshua buys 2 kg of sugar and Venita buys 5 kg of sugar. How many kilograms of sugar do they have together?
4 Nosa’s mass is 30 kg. Bisi’s mass is 24 kg. How many kilograms less is Bisi’s mass than Nosa’s?
 Pupils attempt their class work 
STEP 4 HOMEWORK  Solve the following: 1 3 kg + 16 kg = ___ (19 kg) 2 26 kg – 13 kg = ___ (13 kg) 3 Jack buys 4 kg of bananas. Wathoni buys 7 kg of bananas. How many kilograms of bananas do they have together?  The pupils writes it in their homework book 
STEP 5 SUMMARY  The teacher summarizes by reminding the pupils that in today’s lesson we have solved addition and subtraction problems that involve mass.
She marks their class works, makes corrections where necessary and commends them positively 

PERIOD 5: Weekly Test/consolidations
TEACHER’S ACTIVITY: The teacher revises all the concepts treated from period 14 and gives the pupils follow through exercises, quiz and tests. She marks the exercises, makes corrections and commends the pupils positively.
PUPIL’S ACTIVITY: The pupils work on the worksheets and exercises give by the teacher individually
CONSOLIDATION
1 Draw the following products each with a different mass:
3 kg tomatoes, 5 kg bananas, 8kg mangoes, 1 kg potatoes. Write down the mass of each product.
2 Use the pictures from Question 1 to complete the following:
a Musa bought bananas and mangoes. What is the total mass of her products?
b I bought tomatoes and potatoes. What is the total mass of my products?
c Zara bought mangoes and tomatoes. What is the total mass of his products?
3 Joshua buys 10 kg of mielie meal and Bisi buys 7 kg of mielie meal. How many more kilograms does Joshua have than Bisi?
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