Ratio facts for kids
A ratio is a way to compare the sizes of two or more things. It tells you how much of one thing there is compared to another. You can show a ratio using a colon (like 1:4:9) or as a fraction (like 2/3).
For example, imagine a school with 20 teachers and 500 students. The ratio of teachers to students would be written as 20:500. You would say this as "20 to 500." Another example: if a cake recipe needs 100 grams of flour, 300 grams of butter, and 25 grams of sugar, the ratio of flour to butter to sugar is 100:300:25. This is read as "100 to 300 to 25."
When we compare different types of quantities, like distance and time (miles per hour), we call this a rate. Rates usually have units, like "miles per hour" or "dollars per item."
Understanding Ratios
Ratios can often be made simpler, just like fractions. Making a ratio simpler means finding an equivalent ratio that uses smaller numbers. This makes it easier to understand the comparison.
Simplifying Ratios
Let's go back to the school example with 20 teachers and 500 students (20:500). To simplify this ratio, we can divide both numbers by the same amount.
How to Simplify
Think about how many students each teacher would have if the students were divided equally. If you divide 500 students by 20 teachers, you get 25 students per teacher. This means for every 1 teacher, there are 25 students. So, the simplified ratio of teachers to students is 1:25.
You can also find this by dividing both sides of the original ratio (20:500) by 20:
- 20 divided by 20 equals 1
- 500 divided by 20 equals 25
So, 20:500 is the same as 1:25. Just like you can write a fraction in different ways (for example, 2/1 is the same as 10/5), you can write a ratio in different ways. The simplified form is often the easiest to use.
Related Ideas
See also
In Spanish: Razón (matemática) para niños
