Second Term Lesson Note for Week Three.
Class : Primary 4
Subject : Mathematics
Topic : Decimal fractions
Duration : 80 Minutes
Period : Double Period
Reference Book :
- New Method Mathematics for Primary Schools, Book 4.
- Lagos State Unified schemes of work for Upper Primary, (Primary 4 – 6).
- Online Resources
Behavioural Objectives : By the end of the lesson learners will be able to :
i. Explain decimal fractions
ii. Convert fractions to decimals
iii. Solve questions on decimal fractions involving addition and subtraction.
Instructional Material : Textbook, Charts and pictures of decimal fractions.
Building Background /connection to prior knowledge : Learners are familiar with fractions as part of whole numbers
Content:
Decimal Fractions
Decimal fraction is the writing of a fraction in decimals. It is made up of whole number, decimal point and decimal fraction.
For the whole numbers, we have unit, tens,hundreds, thousands.
For the decimal fractions, we have tenths, hundredth, thousandth, etc.
Tenths = 1/10, (The first digit after the decimal point). For example : 0.2, 0.5, 0.4, etc.
Hundredths = 1/100, (The second digit after the decimal point). For example : 0.02, 0.03, 0.07, 0.09, etc.
Thousandth = 1/1000, (The third digit after the decimal point). For example : 0.001, 0.005, 0.006, 0.008, etc.
For example, fractions can be changed to decimal by carrying out long division.
1/2 = 0.5
1/5 = 0.2
2/5 = 0.4
1/4 = 0.25
3/4 = 0.75
1/8 = 0.125
3/8 = 0.375
7/8 = 0.875
In the number 25.674, Twenty five point six seven four.
2 = 2Tens = 20
5 = 5 Unit = 5
6 = 6 tenths = 6/10 = 0.6
7 = 7 hundredths = 7/100 = 0.07
4 = 4 thousandth = 4/1000 = 0.004
Solving questions on decimal fractions
When solving decimal fractions, arrange the number making sure the decimal point is on a straight line.
1.) 21.34 + 8.11 =
2 1. 3 4
+ 8. 1 1
______________
2 9. 4 5
______________
2.) 15.2 – 4.2 =
1 5. 2
– 4. 2
1 1. 0
Evaluation: Teacher ask pupils questions as regards the lesson explained.
1.) What is the place value of 5 in the given numbers below :
i.) 2.579 = _____________________
ii.) 5.348 = ____________________
iii.) 0.956 = ___________________
iv.) 48.105 = ___________________
2.) Write in words :
i.) 12.04 = ______________________________
ii.) 275.391 = ___________________________
iii.) 8.6 = _______________________________
3. Solve the following decimal fractions
i.) 4.2 + 15.2 =
ii.) 58.97 + 21.2 =
iii.) 16. 75 – 3.25 =
iv.) 10.02 – 5.12 =
Conclusion : At the end of the lesson learners were able to answer the questions correctly.
Assignment :
1. Mrs. Bello bought 16.25m of red ribbon and 4.5m of black ribbon. How much ribbon did she buy altogether?
2. Find the sum of 23.542, 27.431 and 12.687
3. Add 4.61 to 2.68.
4. 7.0 – 5.6
5. Subtract 5.769 from 13.033
6. A bag of rice weighs 7.50kg. A bag of sugar weighs 2.25kg. What is the difference in their weights?