Multiplication and Division
Definition
Multiplication and division are fundamental arithmetic operations that extend the concepts of addition and subtraction. Multiplication is repeated addition, while division is the process of splitting a quantity into equal groups or finding how many groups can be made.
Prerequisites
To understand multiplication and division, you should have mastered:
Learning Objectives
After mastering multiplication and division, you should be able to:
- Understand multiplication as repeated addition
- Memorize basic multiplication facts (up to 12×12)
- Apply the commutative property of multiplication
- Understand division as sharing or grouping
- Recognize the relationship between multiplication and division
- Solve word problems involving multiplication and division
- Use arrays to represent multiplication and division
Key Concepts
Multiplication Concepts
- Repeated addition
- Arrays and area models
- Skip counting
- Properties:
- Commutative (a × b = b × a)
- Associative ((a × b) × c = a × (b × c))
- Distributive (a × (b + c) = ab + ac)
Division Concepts
- Equal sharing
- Equal grouping
- Repeated subtraction
- Fact families with multiplication
Properties and Relationships
- Multiplication and division as inverse operations
- Zero and one properties
- Relationship to fractions
Examples
Example 1: Basic Multiplication (Grade 2)
Problem: What is 4 × 3?
Solution: 1. Think of it as repeated addition: 3 + 3 + 3 + 3 2. Or use an array:
* * *
* * *
* * *
* * *
Example 2: Basic Division (Grade 3)
Problem: Share 15 cookies equally among 3 children.
Solution: 1. Start with 15: ○○○○○○○○○○○○○○○ 2. Make 3 equal groups: Child 1: ○○○○○ Child 2: ○○○○○ Child 3: ○○○○○ 3. Count each group: 5 4. Therefore, 15 ÷ 3 = 5
Example 3: Word Problem (Grade 3)
Problem: A classroom has 6 rows of desks with 4 desks in each row. How many desks are there in total?
Solution: 1. Identify operation needed: multiplication 2. Set up equation: 6 × 4 3. Solve using array model or facts 4. 6 × 4 = 24 5. Answer: There are 24 desks in total
Common Misconceptions
- Thinking multiplication always makes bigger
- Confusing multiplication and addition
- Not understanding the relationship between multiplication and division
- Thinking division is commutative like multiplication
Progression Path
This skill leads to:
Practice Activities
- Basic: Practice multiplication facts 0-5
- Intermediate: Solve division problems with remainders
- Advanced: Word problems with multiple operations
- Challenge: Find patterns in multiplication tables