First Term Lesson Note for Week Six
Class : Primary Three
Subject : Mathematics
Topic : Equivalent, Ordering and Addition of Fractions
Duration : 80 Minutes
Period : Double Period
Reference Book :
- New Method Mathematics for Primary Schools, Book 3.
- Lagos State Unified schemes of work for lower Primary, (Primary 1 – 3).
- Online Resources
Instructional Material : Chart showing fractions on number lines
Learning Objectives : By the end of the lesson learners will be able to :
i. Explain the meaning of equivalent fractions
ii. Explains Ordering of fractions.
iii. Explains like fractions and unlike fractions.
iv. Add and subtract fractions with the same denominator.
Content :
Equivalent Fractions
Equivalent fractions are fractions that are equal or the same. To get equivalent fractions, we divide or multiply both the numerator and denominator by the same number.
1.) 1/3 = 2/6 = 3/9 = 4/12 ( increasing to the right hand side) .
You multiply the numerator and denominator of the given fraction with the same number to give us the equivalent fractions.
1 × 2 = 2 and 3 × 2 = 6 ==> 2/6;
1 × 3 = 3 and 3 × 3 = 9 ==> 3/9;
1 × 4 = 4 and 3 × 4 = 12 ==> 4/12.
Therefore, the equivalent fractions of are : 1/3 = 2/6 = 3/9 = 4/12
2.) 18/24 = 9/12 = 6/8 = 3/4 (decreasing to the right hand side).
You divide the numerator and denominator with the same number to get the equivalent fractions.
18 ÷ 2 = 9 and 24 ÷ 2 = 12 ==> 9/12;
Also, 18 ÷ 3 = 6 and 24 ÷ 3 = 8 ==> 6/8;
18 ÷ 6 = 3 and 24 ÷ 6 = 4 ==> 3/4.
Therefore, the equivalent fractions of 18/24 are : 18/ 24 = 9/12 = 6/8 = 3/4.
Ordering of Fractions
When ordering fractions, we can make use of :
1. Number lines : Represent fractions on a number line.
2. Common denominator : To compare fractions, we write each fraction such that they have same denominator.
Consider : 2/3 and 3/4.
2/3 = (2 × 4)/ (3 × 4) = 8/12
3/4 = (3 × 3) / ( 4 × 3) = 9/12
Compare 8/12 with 9/12. We can see that 8 is less than 9.
Hence, 8/12 is less than 9/12. Therefore, 2/3 < 3/4 or 3/4 > 2/3.
Liked and Unlike Fractions
Liked Fractions : These are set of fractions with the same denominator.
For examples : 3/5 and 1/5, 2/3 and 1/3, 4/7 and 3/7
Unlike fractions : These are pair of fractions with different denominator.
For examples : 1/3 and 3/4; 3/5 and 2/7; 5/9 and 4/9.
Addition and Subtraction of Fractions with same denominator:
Add these fractions :
i. 2/5 + 1/5 = 3/5
ii. 3/7 + 3/7 = 6/7
iii. 5/10 + 2/10 = 7/10
Note : When adding fractions with same denominator, just add up the numerators and then write the answer of the addition with one of the denominator since they are the same.
Subtract these fractions :
i. 2/3 – 1/3 = (2 – 1) / 3 = 1/3
ii. 4/5 – 3/5 = (4 – 3) / 5 = 1/5
iii. 7/9 – 2/9 = ( 7 – 2) / 9 = 5/9.
Note : When subtracting a fraction with the same denominator, subtract the enumerators from each other, then write the answer over one of the denominator.
Presentation Steps :
Step 1 : The teacher revises the previous lesson with the learners.
Step 2 : He/ she introduces the new topic by explaining equivalent fractions and gives examples
Step 3 : Then asks learners to order fractions from the smallest to largest and vice – versa.
Step 4 : Explains the likes and unlike fractions with examples.
Step 5 : Solve simple addition and subtraction of Fractions with same denominator.
Evaluation :
1. Find the equivalent fractions of
i. 1/2 = ( ) / 8 = 16 / ( )
ii. 2/3 = ( ) / 6 = 10/ ( )
2. Add these fractions :
i. 1/4 + 2/4 =
ii. 3/7 + 2/7 =
iii. 4/9 + 4/9 =
3. Subtract these fractions :
i. 9/10 – 4/10 =
ii. 5/6 – 2/6 =
iii. 2/3 – 1/3 =
Conclusion : At the end of the lesson learners were able to answer the questions correctly.