← Back to Grade 7 Topics
Ratios & Proportional Relationships
Understanding Ratios
A ratio is a comparison of two quantities. It tells us how much of one thing there is compared to another. Ratios can be written in three ways: • Using a colon → 3:4 • As a fraction → 3/4 • Using the word "to" → 3 to 4 For example, if there are 3 red marbles and 4 blue marbles, the ratio of red to blue is 3:4.
Example:
In a classroom, there are 12 boys and 15 girls. The ratio of boys to girls is 12:15. We can simplify this ratio by dividing both numbers by their greatest common factor (3): 12 ÷ 3 = 4 15 ÷ 3 = 5 So the simplified ratio is 4:5.