Lesson Planning of Addition and Subtraction of Units of Capacity
Subject Mathematics
Grade 4^{th}
Students` Learning Outcomes
 Add and subtract expressions involving units of capacity / volume.
 Use appropriate unit to measure the capacity / volume of different objects.
 Solve real life problems involving conversions addition and subtraction of units of capacity / volume.
Information for Teachers
 There are two standard units of capacity / volume that are liter (L), and millimetres (ML)
 If liters & millilitres appear in mixed form in any expression then we write liters & millilitres separately below the headings of liter and millilitre.
 After writing the data below the columns we add or subtract.
 Liter can be converted into millilitres by multiplying liters with 1000 so, ml = l x 1000 ml.
 Milliners can be converted into liters by dividing with 1000 so.
 During this lesson consult at each level = ml/1000 where it needed.
Material / Resources
Writing board, chalk/marker, duster, flashcards, empty bottles of different capacities, bucket, cup, jug, syringe and textbook
Introduction
 Ask the students when you go to petrol pump, in which “units” petrol is filled? (Expected answer would be as; liters)
 Tell them that we make columns of liters and millilitres separately and below each column we write number of liters or millilitres and then add or subtract same units.
 Recall the methods of conversion of units.
 If we want to convert greater unit in small then we use multiplication and use division if we want to convert smaller unit in greater one.
Development
Activity 1

Activity 2

Activity 3

Sum up / Conclusion
 If we want to convert greater unit in small then we use multiplication and use division if we want to convert smaller unit in greater one.
 Only same units can be added or subtracted if liters & millilitres appear in mixed from in any expression then we write liters & millilitres separately below the heading of liter and millilitre.
Assessment
 Ask them to solve the following questions in their notebooks: as;
 Check their work and guide them if they feel any problem.
Follow up
 Assign following types of questions to assess the learning level of the students.
 3 l 560 ml of cold drink was served to guests, while 1 l 440 ml was used. How much cold drink remained?
 A drum contains 17 l 680 ml of oil. Another drum “B” contains 11 l 132 ml of oil. What is the total quantity of oil in both drum?