What is 75% as a Decimal?

S1-SA2-0868

Grade Level:

Class 5

Maths, Finance, Data Science, AI

Definition

What is it?

To convert 75% to a decimal, we need to understand that 'percent' means 'out of 100'. So, 75% simply means 75 out of 100. To change this fraction into a decimal, we divide the number by 100.

Simple Example

Quick Example

Imagine your school gave you a test with 100 marks. If you scored 75 marks, that means you got 75% of the total marks. To write this as a decimal, you'd say you scored 0.75 of the total marks.

Worked Example

Step-by-Step

Let's convert 75% to a decimal step-by-step:
1. Understand what 'percent' means: 'per cent' means 'per 100' or 'out of 100'.
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2. Write 75% as a fraction: 75/100.
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3. To convert a fraction to a decimal, divide the numerator (top number) by the denominator (bottom number).
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4. Divide 75 by 100.
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5. When you divide by 100, you simply move the decimal point two places to the left.
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6. Imagine 75 as 75.0. Moving the decimal two places left gives 0.75.
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So, 75% as a decimal is 0.75.

Why It Matters

Understanding percentages and decimals is super useful! From calculating discounts on your favourite clothes (Finance) to understanding how much battery is left on your phone (Data Science), these concepts are everywhere. Even AI and machine learning models use decimals and percentages to make decisions, helping build smart apps and self-driving cars.

Common Mistakes

MISTAKE: Writing 75% as 7.5 | CORRECTION: Remember to divide by 100, which means moving the decimal two places to the left, not just one.

MISTAKE: Thinking 75% as a decimal is 75 | CORRECTION: 75 is a whole number, while 75% is a part of a whole. A decimal always represents a part of a whole (unless it's 100% which is 1).

MISTAKE: Forgetting the leading zero and writing .75 | CORRECTION: While .75 is mathematically correct, it's good practice to write 0.75 to clearly show there are no whole numbers before the decimal point, especially in calculations.

Practice Questions

Try It Yourself

QUESTION: Convert 25% to a decimal. | ANSWER: 0.25

QUESTION: A shop offers a 50% discount. What is this discount as a decimal? | ANSWER: 0.50 (or 0.5)

QUESTION: If a recipe asks for 75% of a cup of milk, and you only have a measuring jug marked in decimals, how much milk (in decimal form) would you add? | ANSWER: 0.75 cups

MCQ

Quick Quiz

What is 75% written as a decimal?

7.5

0.75

0.075

The Correct Answer Is:

To convert a percentage to a decimal, you divide by 100. Dividing 75 by 100 means moving the decimal point two places to the left, which gives 0.75. Options A, B, and D show incorrect decimal placements.

Real World Connection

In the Real World

When you check your mobile data usage, you often see it as a percentage, like '75% data used'. If you wanted to calculate exactly how many GBs that is, you'd convert 75% to 0.75 and then multiply it by your total data plan. For example, if you have a 2 GB plan, 0.75 * 2 GB = 1.5 GB used.

Key Vocabulary

Key Terms

PERCENT: means 'out of 100' | DECIMAL: A way to write numbers that are not whole, using a decimal point | NUMERATOR: The top number in a fraction | DENOMINATOR: The bottom number in a fraction | DIVISION: Splitting a number into equal parts

What's Next

What to Learn Next

Great job understanding percentages as decimals! Next, you can learn 'How to convert Decimals to Percentages'. This will help you switch between the two forms easily and solve more complex problems in everyday life and future math topics.