Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Today, we will learn about ratios. A ratio compares two quantities. For instance, if you have 20 apples and 5 oranges, what is the ratio of oranges to apples?
It's 5 to 20, right?
Exactly! We can simplify this ratio to 1:4. This means for every orange, there are four apples. Can anyone remember how we can also express ratios using fractions?
Isn’t it like 5 over 20?
Correct! And when we simplify it, it becomes 1/4. This helps us visualize the ratio clearly. Remember, ratios help us compare quantities quickly!
Now, let’s transition to percentages. If there are 5 oranges out of a total of 25 fruits, how do we find the percentage of oranges?
We can do it by setting a relationship with 100!
Exactly! We multiply the fraction of oranges by 100. So, 5/25 times 100 equals 20%. Awesome! Can someone tell me what percentage that leaves for apples?
80%! Because 100% minus 20% equals 80%.
Great job! This is how percentages help us to visualize parts of a whole.
Let's put our knowledge into practice. At a picnic, 60% of the students are girls, and there are 18 girls. How can we find the total number of students?
We can set up an equation! If 60% of the total is 18, then we could find the total number of students by dividing.
Yeah! 60% means there's a ratio of 60 to 100, right?
Perfect! So, 18 is to x as 60 is to 100. What do you think x equals?
30! Because 18 times 100 divided by 60 gives us 30.
Exactly! You see how these concepts work together? Percentages can help us break down larger problems into simpler parts.
To find a ratio, oh so neat, count the parts that you can meet.
Imagine a fruit market where for every banana, there are four apples. That’s the tale of the apples and bananas, representing a ratio of 1:4.
To remember how to find percentages, think P-ART (Part, All, Rate × 100).
RAP (Ratio, Adding, Percentage) to remember how to handle ratios and percentages.
Term
What does a ratio of 1:4 represent?
Click to flip
Term
How do you convert a ratio to a percentage?
Click to flip
This section introduces the concepts of comparing quantities using ratios, percentages, and practical applications in everyday situations.
The section elaborates on ratios and percentages, presenting various methods to compare different quantities effectively. It includes examples of real-life applications like calculating the cost per head for an outing and determining percentages of a total, reinforcing these concepts through exercises and discussions.
In this section, we explore how to compare quantities using ratios and percentages. Ratios express the relationship between two quantities, while percentages are used to indicate a number as a fraction of 100. For instance, the section illustrates calculating the percentage of fruits in a basket and delves into practical problems involving class participation and costs associated with a picnic. By applying the unitary method and various calculations, students learn how to determine ratios and percentages in different contexts. The significance of these concepts is highlighted through exercises and real-world scenarios, encouraging critical thinking and application of mathematics in daily life.