Grade 6 → Ratio and Proportion → Ratios ↓
Understanding Ratios
In math, a ratio is a way of comparing two or more quantities. We often use ratios when we need to compare the size, volume, or other quantities of things. Understanding ratios is an important skill in everyday life as it helps us understand numbers and compare things fairly. In Class 6, learning about ratios becomes fundamental as it lays the groundwork for advanced math topics like ratios, algebra, and probability.
What is the ratio?
A ratio shows the relative size of two or more values. A simple way to think of a ratio is like a fraction that compares two quantities. You can write a ratio in a variety of ways, but the most common ways are:
- Use of colon: e.g.
3:4
- As a fraction: such as
3/4
- With the word "to": such as "3 to 4"
Understanding ratios through examples
Let us take the example of a fruit basket containing 6 apples and 3 oranges. The ratio of apples and oranges in this basket can be written as:
6:3
6/3
- "6 to 3"
The ratio tells us that there are 3 oranges for every 6 apples. We can simplify this ratio by dividing both sides of the ratio by the greatest common divisor of 6 and 3, which is 3:
6:3 is simplified to 2:1
So the simplified ratio of apples and oranges is 2:1
This means that for every 2 apples there is 1 orange.
Visual example
Below is a simplified illustration of the ratio of apples and oranges:
Simplifying ratios
Simplifying ratios is like simplifying fractions. When simplifying a ratio, you are reducing it to its smallest whole number representation, where the two quantities cannot be divided by a common factor other than 1. Like simplifying the example above from 6:3
to 2:1
, simplification makes communication clearer and makes comparisons easier.
Example
Consider a scenario where you have made 16 cupcakes and your friend has made 8. The ratio of your cupcakes to your friend's cupcakes is:
16:8
Now, let's simplify this ratio by dividing both numbers by their greatest common divisor. The divisor is 8.
16 ÷ 8 = 2 8 ÷ 8 = 1
The simplified ratio is 2:1
This means you have twice as many cupcakes as your friend.
Equivalent ratio
Equivalent ratios are ratios that show the same relationship between quantities, even though they look different. To find an equivalent ratio, you can multiply or divide both terms of the ratio by the same number.
Example: Finding equivalent ratios
Let's go back to the fruit basket in which the ratio of apples and oranges is 2:1
. Here are some equivalent ratios:
2:1 × 2 = 4:2 2:1 × 3 = 6:3 2:1 × 4 = 8:4
All the above ratios express the same relationship: for every two units of apples there is one unit of oranges.
Using equivalent ratios
Equivalent ratios help compare different scenarios. For example, if you know a recipe uses a ratio of 2 parts flour to 1 part sugar, and you need to make three times as much dough as the recipe calls for, you'll need 6 parts flour and 3 parts sugar, maintaining a flour-to-sugar ratio of 6:3
.
Ratio in real life situations
Ratios are everywhere in the real world. Let's look at some scenarios where understanding ratios is important:
Cooking and recipes
Ratios are often used in recipes to ensure the right balance of ingredients. Let's say a smoothie recipe calls for 3 cups of strawberries for every 1 cup of milk. If you want to double the recipe, ratios help keep the balance right, maintaining the proportions:
6:2
Map and scale
Maps use ratios to indicate scale. If the scale of a map is 1:1000, it means that 1 unit on the map (such as a centimeter) translates to 1000 units (centimeters) in real life. If you measure 5 centimeters on the map, this represents:
5:5000
in the real world.
Financial literacy
It is important to understand the payment ratio, interest and other financial concepts. If the ratio of savings and spending in the budget is 1:3, it indicates that for every 3 units of money spent, 1 unit of money is saved.
Using ratios for comparison
Ratios are great for making comparisons between different quantities. This can be useful in analyzing situations to make decisions.
Example: Comparing prices
Imagine you are at a store to buy juice. Brand A offers 2 liters of juice for $6, and brand B offers 3 liters of juice for $9. To compare these offers, you can use the ratio:
Brand A: $6/2 = $3 per liter
Brand B: $9/3 = $3 per liter
The price per litre is the same for both brands, making it a similar cost option.
Solving a problem using ratios
Ratios are a great tool for solving problems that involve relationships between quantities. Here's how to solve common problems:
Example: Sharing in a given ratio
If you need to divide 12 candies between two friends in a 2:1 ratio, the first step is to determine how many parts there are in the ratio:
Ratio 2:1 = 2 + 1 = 3 parts
Divide the candies into 3 parts: 12 candies ÷ 3 = 4 candies per part.
Friend 1: 2 parts × 4 candies = 8 candies Friend 2: 1 part × 4 candies = 4 candies
Conclusion
Understanding ratios is an important mathematical skill that helps compare quantities, predict results, and solve real-world problems. By breaking down the concept of ratios through simple examples, visual illustrations, and practical applications, we can understand how ratios play an important role in understanding and organizing various aspects of daily life.
Such basic concepts are not just about numbers, but apply widely, from cooking recipes to financial planning. Remember, practicing with real scenarios strengthens your ability to use ratios naturally and confidently in everyday situations.