Why do we use division when we use per something?

In summary, division and fractions are used to represent "per" because it indicates both division and fraction. For example, 3 per hundred means 3 out of 100, which can be expressed as a ratio or a fraction. This is also seen in other units, such as mph, where we are talking about a ratio of miles driven per time in hours.
  • #1
Cash Fulton
24
1
Why do we use division/fractions to represent per something?
 
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  • #2
Three per hundred, for example, means 3 out of 100, so we can write it as a ratio, 3:100, or a fraction, 3/100
 
  • #3
3 per hundred is 3:97.
 
  • #4
pasmith said:
3 per hundred is 3:97.
Ah yes, good catch. I should have said "three out of a hundred, or 3/100"
 
  • #5
phinds said:
Three per hundred, for example, means 3 out of 100, so we can write it as a ratio, 3:100, or a fraction, 3/100
Doesn't really answer my question. I am asking why that is.
 
  • #6
Cash Fulton said:
Doesn't really answer my question. I am asking why that is.
Why it is, is because of what the words mean. When we say, for example, 6 per cent (literally 6 per 100) we are expressing a ratio: ##\frac 6 {100}##. It's similar for units such as mph (miles per hour). We are talking about a ratio of miles driven per (divided by) the time in hours.
 
  • #7
"per" distinctly indicates both DIVISION and FRACTION.
 

1. Why do we use division when we use per something?

Division is used when we want to find the ratio or the amount of one quantity in relation to another quantity. In this case, "per something" represents the second quantity, and division helps us determine the amount or quantity of the first quantity in relation to the second.

2. Can't we just use multiplication instead of division when using "per something"?

While multiplication and division are inverse operations, they serve different purposes. Multiplication is used when we want to find the total amount or quantity of something, while division is used when we want to find the amount of something in relation to another quantity. Therefore, division is more appropriate when using "per something" as it helps us determine the specific amount or quantity we are interested in.

3. Is division the only way to express "per something"?

No, there are other ways to express "per something" such as using fractions, ratios, or percentages. However, division is the most common and simplest way to express this concept.

4. How is division used in real-life situations when using "per something"?

Division is used in various real-life situations that involve rates, such as calculating the price per unit of an item, the speed per hour of a vehicle, or the percentage increase or decrease of a population over time. It is also commonly used in financial and scientific calculations.

5. Why is it important to understand division when using "per something"?

Understanding division is crucial when using "per something" as it allows us to accurately calculate and compare quantities in relation to each other. It also helps us make informed decisions, such as determining the most cost-effective option when comparing prices per unit or analyzing trends and patterns in data.

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