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What is 9 - 1?
Grade Level:
Class 1
Maths, Computing, AI
Definition
What is it?
9 - 1 is a basic subtraction problem. It means taking away 1 from the number 9. Subtraction helps us find how many are left when some items are removed.
Simple Example
Quick Example
Imagine you have 9 yummy ladoos on a plate. If your friend eats 1 ladoo, how many ladoos are left for you? You started with 9, and 1 was taken away.
Worked Example
Step-by-Step
Let's find out what is 9 - 1.
---Step 1: Start with the first number, which is 9.
---Step 2: The minus sign (-) means we need to take away or subtract.
---Step 3: The second number is 1, so we need to take away 1 from 9.
---Step 4: Count backwards 1 step from 9. So, 9, then 8.
---Step 5: The number we land on is 8.
So, 9 - 1 = 8.
Why It Matters
Understanding subtraction is the first step for many advanced topics in Maths, Computing, and even AI. Computer programmers use subtraction for calculations, and data scientists use it to compare numbers. It's a fundamental skill for problem-solving in any field.
Common Mistakes
MISTAKE: Counting forward instead of backward. For example, some might think 9 - 1 is 10. | CORRECTION: Remember, subtraction means taking away or reducing, so you should always count backward from the starting number.
MISTAKE: Not starting from the correct number. For example, starting from 1 and counting up to 9. | CORRECTION: Always start counting from the first number given in the problem (in this case, 9) and then subtract the second number.
MISTAKE: Confusing subtraction with addition. For example, thinking 9 - 1 is the same as 9 + 1. | CORRECTION: The minus sign (-) means 'take away,' while the plus sign (+) means 'add on.' They are opposite operations.
Practice Questions
Try It Yourself
QUESTION: You have 7 crayons. If you give 1 crayon to your friend, how many do you have left? | ANSWER: 6
QUESTION: A bus has 10 seats. If 1 seat is empty, how many seats are filled? | ANSWER: 9
QUESTION: Your elder sister scored 9 runs in a cricket match. If she needed 1 more run to reach 10, how many runs did she actually score? (Think: 10 minus 1) | ANSWER: 9
MCQ
Quick Quiz
What is the result of 9 minus 1?
10
8
9
1
The Correct Answer Is:
B
When you take 1 away from 9, you are left with 8. Options A, C, and D are incorrect as they represent addition, the original number, or the number being subtracted, respectively.
Real World Connection
In the Real World
Every day, we use subtraction without even realizing it. When you're buying vegetables and pay with a 100-rupee note for something that costs 90 rupees, the shopkeeper uses subtraction to give you back 10 rupees change. Or when you check your phone's data usage: if you started with 1 GB and used 0.1 GB, you subtract to see how much is left!
Key Vocabulary
Key Terms
SUBTRACTION: Taking one number away from another | MINUS: The symbol (-) used for subtraction | DIFFERENCE: The answer you get after subtracting | COUNT BACKWARD: Starting from a number and counting downwards
What's Next
What to Learn Next
Great job mastering basic subtraction! Next, you can learn about 'What is 9 - 2?' and 'What is 8 - 3?'. These will help you practice subtracting larger numbers and build a strong foundation for more complex math problems.
