Unit 2 - Lesson 3 (More Proportions)

Summary

In this instructional video, the teacher revisits the concept of proportions, explaining that they consist of two equal ratios. Through examples, students learn to identify equivalent ratios using cross-multiplication and simplification techniques. The lesson also emphasizes equivalent fractions as another method to demonstrate proportional relationships. Students are encouraged to practice these concepts with a worksheet provided in Google Classroom. By integrating real-life examples and various engagement strategies, the instructor aims to deepen students' understanding of proportions and their practical applications.

Takeaways

• 😀 A proportion is defined as two equal ratios.
• 😀 To check if two ratios are proportional, you can use cross-multiplication.
• 😀 Example of non-proportional ratios: 42/3 and 30/5, as 42 × 5 does not equal 3 × 30.
• 😀 Example of proportional ratios: 9/64 and 48/12, since both yield the same product when cross-multiplied.
• 😀 Simplifying ratios can also help determine if they are proportional.
• 😀 Example: 8/32 simplifies to 1/4, which is proportional to 3/12 (also simplifies to 1/4).
• 😀 Equivalent fractions can be used to check for proportionality by multiplying the numerator and denominator by the same number.
• 😀 Example: The fraction 2/3 generates equivalent fractions like 4/6, 6/9, and so on.
• 😀 Students are encouraged to practice finding proportions through a worksheet available on Google Classroom.
• 😀 Calculators can be used for calculations to make the process easier for students.

Q & A

What is the main topic of Unit 2, Day 3?

The main topic is understanding proportions, specifically the concept of equivalent ratios.

How does the instructor define a proportion?

A proportion is defined as two ratios that are equal.

What method does the instructor use to determine if the ratios 42/3 and 30/5 are proportional?

The instructor uses cross-multiplication to check if the two ratios are proportional.

What were the results of the cross-multiplication for the ratios 42/3 and 30/5?

The results showed that 42 * 5 equals 210, while 3 * 30 equals 90, indicating that the ratios are not proportional.

What is the outcome when cross-multiplying the ratios 9/64 and 48/12?

Both calculations equal 576, which confirms that the ratios 9/64 and 48/12 are proportional.

What technique does the instructor suggest for simplifying ratios?

The instructor suggests finding a common number that divides both terms of the ratio to simplify it.

How does the instructor demonstrate the concept of simplifying ratios using 8 and 32?

The instructor shows that 8 goes into 8 once and into 32 four times, simplifying the ratio to 1/4.

What example does the instructor give to explain equivalent fractions?

The instructor uses 2/3 and shows how multiplying the numerator and denominator by the same number results in equivalent fractions like 4/6 and 6/9.

What is a disadvantage of using the equivalent fractions method to determine proportionality?

It can be time-consuming and complex, making it less practical for quick calculations.

What assignment does the instructor give at the end of the lesson?

Students are assigned to complete a worksheet available on Google Classroom and can use their laptops for calculations.