Thursday, August 30, 2007

Introduction to Multiplication

Objectives:
- To understand the concept of multiplication using repeated addition, skip counting, groupings, and number line.
- To convert repeated addition process into multiplication process and vice-versa.
- To be able to give accurate counting.
- To manipulate objects with precision.
- To be able to work in groups.

Materials: strips of paper, papers, pencil, blackboard, beans,
some pieces of string

Procedure:

1. Drill the students on their skip counting skill.


Examples: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20.
3, 6, 9, 12, 15, 18, 21, 24, 27, 30
4, 8, 12, 16, 20, 24, 28, 32, 36, 40
5, 10, 15, 20, 25, 30, 35, 40, 45, 50
10, 20, 30, 40, 50, 60, 70, 80, 90, 100


2. Write on the blackboard: 2 + 2 + 2 + 2 +2 = 10


Introduce multiplication: Explain that there is a fast process to express this repeated addition and it is, 5 x 2 = 10. How many times is 2 added? (5x). Give some more similar exercises.

3. Draw on the blackboard, four circles, and in each circle, draw three dots. Explain that the multiplication process can be used here to come out with the total number of dots. Thus:
4 (circles) x 3 (dots) = 12 dots - Substitute circles and dots with other figures such as stars.
Give some more of these similar exercises to reinforce this skill.

4. Draw a number line. Show this on the number line.
5 x 3 = 15
1 2 3
__________________x____________________x________________________x
i_____i_____i____i______i_____i______i____i____i_____i______i______i______i______i_____i_______i_____i__
1 2 3 4 (5) 6 7 8 9 (10) 11 12 13 14 (15) 16
Give some more of these similar exercises using number line.

5. Evaluation.
Have the students complete the following exercises.
Solve the following using repeated addition, groupings, and number line: 4 x 4 = _______; 3 x 7 = _______; 6 x 5 = _______

Show some exercises in repeated addition, groupings, or in number lines to be expressed in multiplication sentences.

6. Enrichment: Distribute beans and strings that have been knotted to make a circular form. Use them to show groupings in multiplication.

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