# Capacity Basic Unit of Measurement Addition and Subtraction in Litres Primary 4 Third Term Lesson Notes Mathematics Week 6

### Fun with Litres: Adding and Subtracting Liquid Volumes!

**Subject:** Mathematics

**Class:** Primary 4

**Term:** Third Term

**Week:** 6

**Topic:** Capacity – Basic Unit of Measurement Addition and Subtraction in Litres

**Sub-topic:** Understanding how to add and subtract volumes using litres

**Duration:** 45 minutes

**Behavioural Objectives:**

- By the end of the lesson, students should be able to add and subtract volumes using litres accurately.
- Students should demonstrate understanding of capacity and its importance in measuring liquids.
- Students should estimate volumes of liquids in various containers.

**Key Words:** Capacity, litres, addition, subtraction, estimation, measurement.

**Entry Behaviour:** Students should be familiar with basic addition and subtraction concepts and have some understanding of measuring liquids.

**Learning Resources and Materials:**

- Whiteboard and markers
- Textbooks (Lagos State Scheme of Work)
- Illustrations of containers with different capacities
- Measuring jugs or cups
- Worksheets for practice

**Building Background/Connection to Prior Knowledge:**

- Begin by asking students if they have ever measured liquids before, such as pouring juice or water into a cup.
- Review basic addition and subtraction by giving examples of adding and subtracting numbers.
- Show illustrations of different containers and discuss how they can hold different amounts of liquid.

**Embedded Core Skills:**

- Numeracy: Adding and subtracting volumes
- Critical thinking: Estimating capacities
- Communication: Expressing ideas and asking questions

**Learning Materials:**

- Textbooks
- Illustrations
- Worksheets

**Reference Books:** Lagos State Scheme of Work for Mathematics

**Instructional Materials:**

- Whiteboard
- Markers
- Illustrations
- Measuring jugs or cups
- Worksheets

**Content:**

**Understanding Capacity**: Capacity is how much a container can hold, like a bottle for water or a cup for juice. It helps us know how much liquid something can store.**Importance of Capacity**: Knowing capacity is important because it helps us measure liquids accurately. It’s like knowing how much water a bucket can hold before it overflows.**Litres as the Basic Unit**: Litres are like the building blocks for measuring capacity. They tell us how much liquid something holds. For example, a small bottle might hold 1 liter, while a big tank can hold hundreds of liters.**Adding Litres**: Adding litres means putting more liquid together. If we have 2 litres of milk and add 3 more litres, we end up with 5 litres altogether. It’s like filling a glass with more juice.**Subtracting Litres**: Subtracting litres means taking away some liquid. If we have 5 litres of soda and drink 2 litres, we’re left with 3 litres. It’s like drinking from a bottle and seeing how much is left.**Real-Life Problems**: We can use our knowledge of capacity and litres to solve everyday problems. Like figuring out how much juice to buy for a party or how much water a tank needs to be full.**Estimation in Capacity**: Estimation means making a good guess. When we estimate capacity, we’re making a smart guess about how much liquid something can hold. It’s like looking at a glass and guessing if it’s half-full or almost full.

So, understanding capacity and litres helps us measure liquids accurately, solve everyday problems, and make good guesses about how much liquid something holds! 📏🥤

**Worked-out examples:**

**Addition Examples**:- If we have 2 liters of juice and add 3 more liters, how much juice do we have in total? Answer: 2 + 3 = 5 liters
- Tom has 4 liters of water, and Mary gives him 2 more liters. How much water does Tom have now? Answer: 4 + 2 = 6 liters
- There are 5 liters of milk in one bottle and 3 liters in another. How much milk is there in total? Answer: 5 + 3 = 8 liters
- I have 1 liter of cola, and my friend brings 6 more liters. How much cola do we have together? Answer: 1 + 6 = 7 liters
- Sarah has 7 liters of lemonade, and she buys 4 more liters. How much lemonade does she have now? Answer: 7 + 4 = 11 liters

**Subtraction Examples**:- If there are 8 liters of orange juice, and 3 liters are poured out, how much juice is left? Answer: 8 – 3 = 5 liters
- Lisa has 6 liters of water, and she drinks 2 liters. How much water does she have left? Answer: 6 – 2 = 4 liters
- There were 10 liters of soda in a bottle, and 5 liters were poured out. How much soda remains? Answer: 10 – 5 = 5 liters
- Jack had 9 liters of milk, but he used 3 liters for baking. How much milk does he have left? Answer: 9 – 3 = 6 liters
- There were 12 liters of fruit punch in a jug, and 7 liters were poured out. How much fruit punch remains? Answer: 12 – 7 = 5 liters

**Mixed Examples**:- Tom has 5 liters of orange juice. If he pours out 2 liters and then adds 3 more liters, how much juice does he have? Answer: (5 – 2) + 3 = 3 + 3 = 6 liters
- Sarah has 8 liters of water. She drinks 4 liters and then buys 5 more liters. How much water does she have now? Answer: (8 – 4) + 5 = 4 + 5 = 9 liters
- There are 6 liters of lemonade in one jug and 9 liters in another. If we pour both into a big container, how much lemonade do we have? Answer: 6 + 9 = 15 liters

**Evaluation**:

- Tom has 3 liters of juice. He buys ____ more liters. How many liters does he have in total? a) 2 b) 4 c) 5 d) 6
- Lisa has 6 liters of water. She pours out ____ liters. How much water does she have left? a) 2 b) 3 c) 4 d) 5
- There are 8 liters of soda in a bottle. If 3 liters are poured out, how many liters remain? a) 2 b) 3 c) 5 d) 8
- Jack has 7 liters of milk. He uses ____ liters for baking. How much milk does he have left? a) 2 b) 3 c) 5 d) 7
- Sarah has 5 liters of lemonade. She buys ____ more liters. How much lemonade does she have now? a) 2 b) 3 c) 4 d) 6
- If there are 10 liters of orange juice and 5 liters are poured out, how many liters are left? a) 2 b) 3 c) 5 d) 10
- Lisa has 4 liters of water. She drinks ____ liters. How much water does she have left? a) 2 b) 3 c) 4 d) 5
- There were 9 liters of soda in a bottle. If 4 liters are poured out, how many liters remain? a) 2 b) 3 c) 5 d) 9
- Sarah has 6 liters of lemonade. She drinks ____ liters and then buys 3 more liters. How much lemonade does she have now? a) 2 b) 3 c) 6 d) 9
- Tom has 2 liters of juice. He adds ____ more liters. How many liters does he have in total? a) 2 b) 3 c) 4 d) 5
- Jack has 8 liters of milk. He uses ____ liters for baking. How much milk does he have left? a) 2 b) 3 c) 5 d) 8
- Lisa has 7 liters of water. She pours out ____ liters and then buys 2 more liters. How much water does she have now? a) 2 b) 3 c) 6 d) 9
- If there are 12 liters of orange juice and 7 liters are poured out, how many liters are left? a) 2 b) 3 c) 5 d) 12
- Sarah has 9 liters of lemonade. She buys ____ more liters. How much lemonade does she have now? a) 2 b) 3 c) 4 d) 6
- There were 6 liters of soda in a bottle. If 2 liters are poured out, how many liters remain? a) 2 b) 3 c) 4 d) 6

**Class Activity Discussion **

- What is capacity?
**Answer**: Capacity is how much liquid a container can hold, like a bottle or a jug. - What do we use to measure capacity?
**Answer**: We use liters to measure capacity. - How do we add liters?
**Answer**: Adding liters means putting more liquid together, like pouring juice into a glass. - Can you give an example of adding liters?
**Answer**: Sure! If we have 2 liters of water and add 3 more liters, we have 5 liters in total. - What about subtracting liters?
**Answer**: Subtracting liters means taking away some liquid, like drinking from a bottle. - Can you give an example of subtracting liters?
**Answer**: Of course! If we have 8 liters of soda and pour out 3 liters, we have 5 liters left. - Why is it important to know about capacity?
**Answer**: Knowing about capacity helps us measure liquids accurately for cooking, drinking, or filling containers. - How can we use our knowledge of capacity in real life?
**Answer**: We can use it to figure out how much juice to buy for a party or how much water a tank can hold. - What is estimation in capacity?
**Answer**: Estimation is making a good guess about how much liquid something can hold without measuring it exactly. - Why do we need to estimate capacity?
**Answer**: Estimation helps us make quick decisions, like guessing how much juice is left in a jug. - Can you give an example of estimation?
**Answer**: Sure! If we look at a glass of water, we might estimate it’s about half-full without measuring it. - How do we know if we estimated correctly?
**Answer**: We can check by measuring the liquid to see if our estimate was close to the actual amount. - Is capacity only for liquids?
**Answer**: No, we can also measure the capacity of containers for things like grains, beans, or even toys! - What is the capacity of a small bottle?
**Answer**: It depends, but a small bottle might hold around 1 liter of liquid. - Can you give an example of using capacity in everyday life?
**Answer**: Sure! When we fill a glass with water, we’re using our knowledge of capacity to know how much water it can hold.

**Presentation:**

**Step 1:** The teacher revises the previous topic which was understanding basic addition and subtraction.

### Time Measurement ; Calendar, date Primary 4 Third Term Lesson Notes Mathematics Week 5

**Step 2:** The teacher introduces the new topic, explaining that today we will learn how to add and subtract volumes using litres. Show examples of different containers and their capacities.

**Step 3:** The teacher allows the pupils to give their own contributions and the teacher corrects the pupils when and where necessary.

**Teacher’s Activities:**

- Explain the importance of measuring liquids accurately.
- Demonstrate how to add and subtract volumes using litres.
- Provide examples and illustrations for better understanding.
- Encourage students to ask questions and participate actively.

**Learners’ Activities:**

- Listen attentively to the teacher’s explanations.
- Participate in discussions and ask questions.
- Practice adding and subtracting volumes using litres.
- Estimate capacities of different containers.

**Assessment:** Observation during class activities, participation in discussions, and completion of worksheets.

**Evaluation Questions:**

- What is capacity?
- What unit of measurement do we use for capacity?
- How do we add volumes using litres?
- How do we subtract volumes using litres?
- Why is it important to estimate capacities?
- Can you estimate the capacity of a glass of water?
- If I have 3 litres of juice and add 2 more litres, how much juice do I have?
- If there are 7 litres of milk and I pour out 4 litres, how much milk is left?
- What do you use to measure liquids at home?
- Can you name three containers with different capacities?

**Conclusion:** The teacher goes round to mark and does the necessary corrections on the topic above. Students are encouraged to practice adding and subtracting volumes using litres at home and to estimate capacities of different containers they encounter.