Lesson Planning of Addition & Subtraction

Lesson Planning of Addition & Subtraction (Units of Time)

Subject Mathematics

Grade 4^th

Students` Learning Outcomes

Add and subtract units of time without carrying / borrowing.
Solve simple real life problems involving conversation, addition or subtraction of units of time.

Information for Teachers

Material / Resources

Writing board, chalk / marker, duster, models of analog and digital clocks [ real if possible], textbook

Introduction

Ask the students how long are your lunch break? (Possible answer would be as; 30 minutes)
After getting their responses ask them, can you tell this time in seconds? (Possible answer would be as; yes).
If yes, then it is equal to how many seconds?
Tell them to convert minutes into seconds we multiply minutes by 60.
Show them a chart of clock and ask them: as;
Look at the clock and ask what the time by now is? (Possible answer would be as; 11:10)
What would be the time after 10 minutes and 15 minutes?
Today we will study to add or subtract units of time and daily life examples.

Development

Activity 1

Hours Minutes

7 35

+ 6 21

13 56

Explain them that we write hours and minutes vertically in the columns.
Hours are added to hours and minutes to minutes.
Now let us see how we can subtract time? 24 hours 44 minutes 56 sends – 12 hours 21 minutes 34 seconds
Ask them to solve the following questions : as;

Hours Minutes Seconds

24 44 56

– 12 21 34

12 23 22

(1) 8 hours 29 minutes + 4 hours 12 minutes

(2) 19 hours 31 minutes – 10 hours 20 minutes

Activity 2

Give real life examples to further strengthen their concepts.
Ask from Rabia. Your mother can cook rice and prepare salad n how much time?
Suppose she says that rice in 2 hours 41 minutes and salad in 10 minutes. Can you calculate how much time she took altogether?
Help in solving this question: as;
Rice took = 2 hours 41 minutes
Salad took = 10 minutes
Total time = 2 hours 41 minutes + 10 minutes = 2 hours 51 minutes.

State another question as Raza completed his homework in 1 hour 15 minutes and Qasim took 1 hour 15 minutes. How much more time Raza took?
Raza took = 2 hours 25 minutes
Qasim took = 1 hour 15 minutes
Difference between their times = 2 hours 25 minutes – 1 hour 15 minutes = 1 hour and 10 minutes.

Hour Minute

2 25

– 1 15

1 10

Sum up / Conclusion

Recall the main concepts so students can further improve their deficiencies.
1 hour = 60 minutes
1 minutes = 60 seconds
Hours can be converted to minutes by multiplying with 60.
Only hours can be added to hour’s minutes to minutes and seconds to seconds.
Assess the students with such sort of questions.
Nadeem spends 1 hour 45 minutes to study and 2 hours 13 minutes to play. How much total time does he serves for both activities?
Complete the following table.

No	Day	Time beginning	Time ending	Time spent at swimming practice
1	Sunday	3 : 30 pm	5 : 15 pm	1 hour and 45 minutes
2	Monday	5 : 00 pm	6 : 30 pm
3	Tuesday	4 : 45 pm	6 : 15 pm
4	Wednesday	5 : 40 pm	6 : 45 pm
5	Thursday	5 : 25 pm	6 : 45 pm
6	Friday	7 : 30 pm	8 : 55 pm
7	Saturday	11 : 10 am	2 15 am
8	Sunday	1 : 40 pm	3 35 pm
9	Monday	4 : 15 pm	5 : 55 pm
10	Tuesday	5 : 10 pm	6 : 25 pm
11	Wednesday	4 : 45 pm	6 : 10 pm
12	Thursday	5 : 25 pm	7 : 40 pm
13	Friday	5 : 40 pm	6 : 55 pm
14	Saturday	11 : 25 am	1 : 55 am

Follow up

Give some homework questions so students may be able to solve more real life examples.
How much time you took for each payer and then add all the five times
Calculate your breakfast, lunch and dinner times.
Calculate time in which you reach to school from home and reach at home from school.