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What is Per Mille (Parts Per Thousand)?
Grade Level:
Class 5
Finance, Science, Computing, AI, Statistics
Definition
What is it?
Per Mille, also known as Parts Per Thousand (PPT), is a way to express a very small fraction or proportion out of one thousand. It tells you how many parts of something there are in every 1000 parts of the whole. The symbol for Per Mille is '‰'.
Simple Example
Quick Example
Imagine your school library has 1000 books. If 5 of those books are about Indian history, then the proportion of history books is 5 Per Mille (5‰). This means for every 1000 books, 5 are history books.
Worked Example
Step-by-Step
PROBLEM: A special type of salt solution needs to have 3 grams of salt for every 1000 grams of water. How do you express this as Per Mille?
STEP 1: Identify the parts and the whole. Here, '3 grams of salt' are the parts, and '1000 grams of water' is the whole.
---STEP 2: Per Mille directly means 'parts per thousand'. So, if you have 3 parts out of 1000, it is simply 3 Per Mille.
---STEP 3: Write it using the symbol. The symbol for Per Mille is ‰.
---ANSWER: The concentration is 3‰.
Why It Matters
Understanding Per Mille helps in many fields! In science, doctors use it to measure things like blood alcohol levels, and environmental scientists use it for water salinity. In finance, it can be used for very small interest rates or fees. Knowing this helps you understand important data and make informed decisions.
Common Mistakes
MISTAKE: Confusing Per Mille (‰) with Percentage (%). | CORRECTION: Percentage is 'per hundred' (out of 100), while Per Mille is 'per thousand' (out of 1000). Always check the symbol or context.
MISTAKE: Forgetting that Per Mille means 'out of 1000'. | CORRECTION: Always remember that 1‰ means 1 part out of 1000 total parts.
MISTAKE: Calculating Per Mille by dividing by 100. | CORRECTION: To find Per Mille, you should divide the 'parts' by the 'whole' and then multiply by 1000, or directly express it if the whole is already 1000.
Practice Questions
Try It Yourself
QUESTION: If a batch of 1000 mangoes has 7 rotten ones, what is the Per Mille of rotten mangoes? | ANSWER: 7‰
QUESTION: A small village has 2000 residents. If 40 of them are doctors, what is the Per Mille of doctors in the village? | ANSWER: 20‰ (40/2000 * 1000 = 20)
QUESTION: A 500-gram packet of mixed dry fruits contains 15 grams of cashews. What is the Per Mille of cashews in the packet? | ANSWER: 30‰ (15/500 * 1000 = 30)
MCQ
Quick Quiz
What does 15‰ mean?
15 out of 100
150 out of 1000
15 out of 1000
1500 out of 100
The Correct Answer Is:
C
Per Mille (‰) means 'parts per thousand'. So, 15‰ means 15 parts out of a total of 1000 parts. Options A, B, and D are incorrect interpretations.
Real World Connection
In the Real World
In India, Per Mille is used in various fields. For example, when measuring the salinity (saltiness) of seawater for fish farming, scientists might say 'the water has 35‰ salinity'. This means for every 1000 grams of water, there are 35 grams of salt. This helps farmers maintain the right conditions for their fish.
Key Vocabulary
Key Terms
PER MILLE: Parts per thousand, meaning 'out of 1000' | PROPORTION: A part, share, or number considered in relation to a whole | SALINITY: The amount of salt dissolved in water | FRACTION: A part of a whole, often written as one number over another
What's Next
What to Learn Next
Great job learning about Per Mille! Next, you can explore 'Percentages' and 'Ratios'. These concepts are very similar and will help you understand how different quantities relate to each other in even more ways. Keep up the good work!
