How to teach half of odd numbers?

The key to teaching how to find half of odd numbers involves breaking the odd number down into an even number plus one. Here's how:

Understanding the Concept

The fundamental concept is that any odd number can be expressed as an even number plus one. This allows us to easily find half of the even number and then add half of one (0.5) to it.

Steps to Teach

1. Identify the Odd Number: Let's say the odd number is 17.

2. Decompose the Odd Number: Break 17 into 16 + 1. (An even number + 1).

3. Find Half of the Even Number: Half of 16 is 8.

4. Find Half of One: Half of 1 is 0.5 or one half (1/2).

5. Combine the Results: 8 + 0.5 = 8.5. Therefore, half of 17 is 8.5. As explained in the Mathnasium video, half of 17 is equal to eight and a half (8 ½).

Example

Let's take another example, 25:

1. Odd Number: 25

2. Decomposition: 24 + 1

3. Half of Even: Half of 24 is 12.

4. Half of One: Half of 1 is 0.5

5. Combination: 12 + 0.5 = 12.5. Thus, half of 25 is 12.5.

Practical Insights

• This method works for all odd numbers.
• Emphasize the concept of breaking down the odd number into manageable parts.
• Using visual aids can help learners grasp the concept more effectively.