Post by Diedra Warner on Jun 8, 2009 9:45:37 GMT -5
Date Monday, 6th April 2009
Subject: Mathematics
Topic: Fractions
Subtopic: Addition and Subtraction of fractions with Unlike Denominators
Grade: Four (4)
Age: 9 to 10 years
No. of Students: Twenty-one (21)
No. of Males: Ten (10) No. of Females: Eleven (11)
Time: 40 to 45 minutes
Materials: Chart with poem
Objectives
a. Having discussed fractions, students should be able to correctly identify fractions with unlike denominators without the aid of the teacher.
b. After working out examples on the board, students should be able to add and subtract fractions with unlike denominators with no more than two errors.
c. Having attempted to solve problems, students should be able to express the steps in adding and subtracting fractions with unlike denominators without looking at the chart.
Previous Knowledge
Students are able to:
i. Identify a fraction
ii. Find the lowest common multiple of two numbers
iii. Recognize improper fractions and mixed numbers
iv. Convert a mixed number to an improper fraction and an improper fraction to a mixed number.
Introduction
Recite a poem to students entitled “Just a Fraction”. The poem is about a fraction that had too much weight and was aspiring to lose some to fit in her dress for a party. The poem relates that in order to lose weight a fraction from the original overweight fraction had to be subtracted. Question students on what they think the poem would have been about. Inform students that the lesson for the day would focus on Addition and Subtraction of Fractions with Unlike Denominators. See Appendix for Poem
Procedure
Step One
Teacher and students will briefly recap together the previous lesson on addition and subtraction of fractions with like denominators. Work through an example on the board with students.
For example: 3/8 + 2/8 =
5/10 – 3/10 =
Step Two
Teacher prints the following problem on the board:
Example: 2/9 + 5/6
Illustrate and work through the example on the board for students. Explain each step in the process for finding the answer with the aid of a chart. See Appendix for Steps in adding and subtracting fractions with unlike denominators
Step Three
Work other examples on the board with students. Elicit from student the steps involved in solving the sum and difference of fractions of unlike denominators.
Step Four
Teacher prints the following problems on the board.
1. 4/5 – 2/3
2. 9/12 + 1/6
3. 5/7 – 2/14
Volunteer students to come to the board and attempt the problems, with an explanation of the procedure for working out the problems.
Step Five
Question children about how adding fractions with unlike denominators is similar to subtracting fraction with unlike denominators. Note students’ responses.
Closure
Recap briefly with students the steps in adding and subtracting fractions with unlike denominators with the aid of the chart.
Application
Students will do the following problems in their books.
1. 11/16 – 2/4
2. 9/10 – 4/5
3. 5/8 – 2/4
4. 5/6 + 3/5
5. 8/12 + 1/3
6. 4/6 + 3/9
Evaluation
Subject: Mathematics
Topic: Fractions
Subtopic: Addition and Subtraction of fractions with Unlike Denominators
Grade: Four (4)
Age: 9 to 10 years
No. of Students: Twenty-one (21)
No. of Males: Ten (10) No. of Females: Eleven (11)
Time: 40 to 45 minutes
Materials: Chart with poem
Objectives
a. Having discussed fractions, students should be able to correctly identify fractions with unlike denominators without the aid of the teacher.
b. After working out examples on the board, students should be able to add and subtract fractions with unlike denominators with no more than two errors.
c. Having attempted to solve problems, students should be able to express the steps in adding and subtracting fractions with unlike denominators without looking at the chart.
Previous Knowledge
Students are able to:
i. Identify a fraction
ii. Find the lowest common multiple of two numbers
iii. Recognize improper fractions and mixed numbers
iv. Convert a mixed number to an improper fraction and an improper fraction to a mixed number.
Introduction
Recite a poem to students entitled “Just a Fraction”. The poem is about a fraction that had too much weight and was aspiring to lose some to fit in her dress for a party. The poem relates that in order to lose weight a fraction from the original overweight fraction had to be subtracted. Question students on what they think the poem would have been about. Inform students that the lesson for the day would focus on Addition and Subtraction of Fractions with Unlike Denominators. See Appendix for Poem
Procedure
Step One
Teacher and students will briefly recap together the previous lesson on addition and subtraction of fractions with like denominators. Work through an example on the board with students.
For example: 3/8 + 2/8 =
5/10 – 3/10 =
Step Two
Teacher prints the following problem on the board:
Example: 2/9 + 5/6
Illustrate and work through the example on the board for students. Explain each step in the process for finding the answer with the aid of a chart. See Appendix for Steps in adding and subtracting fractions with unlike denominators
Step Three
Work other examples on the board with students. Elicit from student the steps involved in solving the sum and difference of fractions of unlike denominators.
Step Four
Teacher prints the following problems on the board.
1. 4/5 – 2/3
2. 9/12 + 1/6
3. 5/7 – 2/14
Volunteer students to come to the board and attempt the problems, with an explanation of the procedure for working out the problems.
Step Five
Question children about how adding fractions with unlike denominators is similar to subtracting fraction with unlike denominators. Note students’ responses.
Closure
Recap briefly with students the steps in adding and subtracting fractions with unlike denominators with the aid of the chart.
Application
Students will do the following problems in their books.
1. 11/16 – 2/4
2. 9/10 – 4/5
3. 5/8 – 2/4
4. 5/6 + 3/5
5. 8/12 + 1/3
6. 4/6 + 3/9
Evaluation