What is Adding Three Numbers?

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Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

Adding three numbers means combining three different quantities or groups to find their total sum. It's like putting three piles of things together and counting how many you have in all.

Simple Example

Quick Example

Imagine your school cricket team scored 25 runs in the first over, 10 runs in the second over, and 5 runs in the third over. To find the total runs after three overs, you would add these three scores together.

Worked Example

Step-by-Step

Let's say you want to find the total cost of three items: a pen for ₹15, a notebook for ₹30, and an eraser for ₹5.

Step 1: Write down the numbers you need to add: 15, 30, and 5.
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Step 2: Start by adding the first two numbers. 15 + 30 = 45.
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Step 3: Now, take the sum from Step 2 (which is 45) and add the third number (which is 5). 45 + 5 = 50.
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Step 4: The final sum is 50.

So, the total cost of the pen, notebook, and eraser is ₹50.

Why It Matters

Understanding how to add three numbers is a basic but very important skill in maths. It helps you manage money, calculate distances, and even plan your daily schedule. This skill is crucial for careers like a shopkeeper, an accountant, or even a scientist who needs to combine different measurements.

Common Mistakes

MISTAKE: Adding only two numbers and forgetting the third one. For example, adding 10 + 20 + 5, and only doing 10 + 20 = 30 and stopping. | CORRECTION: Always make sure you add ALL the numbers given in the problem.

MISTAKE: Making calculation errors when adding numbers with multiple digits, especially when carrying over. For example, adding 15 + 27 + 8 incorrectly. | CORRECTION: Practice column addition carefully, lining up the digits by place value (ones, tens, hundreds) and remembering to carry over correctly.

MISTAKE: Getting confused by the order of addition. For example, thinking you must always add the first two numbers first. | CORRECTION: The order of addition does not matter. (10+5)+20 gives the same result as 10+(5+20). You can add numbers in any order you find easiest.

Practice Questions

Try It Yourself

QUESTION: Your mom bought 3 bags of vegetables. One bag had 2 kg of potatoes, another had 3 kg of onions, and the third had 1 kg of tomatoes. What is the total weight of the vegetables? | ANSWER: 2 + 3 + 1 = 6 kg

QUESTION: A library has 45 storybooks, 20 science books, and 15 drawing books. How many books are there in total? | ANSWER: 45 + 20 + 15 = 80 books

QUESTION: During a sale, a shirt costs ₹299, a pair of jeans costs ₹450, and a cap costs ₹125. What is the total amount you need to pay if you buy all three items? | ANSWER: 299 + 450 + 125 = ₹874

MCQ

Quick Quiz

What is the sum of 12, 8, and 5?

The Correct Answer Is:

To find the sum, first add 12 and 8, which gives 20. Then, add 5 to 20, which gives 25. So, the correct answer is 25.

Real World Connection

In the Real World

When you buy groceries at a local kirana store and pick three different items, the shopkeeper quickly adds up their prices in their head or using a small calculator to tell you the total bill. This is exactly adding three numbers. Even when planning a road trip, you might add the distance to your first stop, then the distance to your second stop, and then to your final destination to get the total journey length.

Key Vocabulary

Key Terms

ADDITION: The process of combining two or more numbers to find their total sum | SUM: The result obtained when two or more numbers are added together | TOTAL: The complete amount or quantity | QUANTITY: An amount or number of something

What's Next

What to Learn Next

Now that you understand how to add three numbers, you're ready to learn about adding more than three numbers, and then moving on to addition with larger numbers and carrying over. Keep practicing, and you'll master addition in no time!