Addition and subtraction Question : Solved

Addition and Subtraction Questions

Edited By Team Careers360 | Updated on Jul 02, 2025 05:29 PM IST

Addition and subtraction are part of the calculation in math. Addition and subtraction are opposite of each other. The addition is combining multiple things and counting them as one large group. In mathematics, the process of combining two or more numbers is called addition. The numbers added are addends, and the final answer is called the sum. (It is usually signified by the plus symbol +) Whereas subtract means to take away from a group or number of things. In mathematics, subtracting means the number of things in the group becomes less or reduces. The parts of subtraction are minuend, subtrahend, and difference. (The - negative symbol usually signifies it).

This Story also Contains

Addition And Subtraction Sum
Addition, Subtraction, Multiplication And Division
Addition And Subtraction For Classes 3 And 4

Addition And Subtraction Sum

Addition and subtraction are inverse operations of each other. As an illustration, if 9 + 1 = 10, then 10 - 1 = 9. That demonstrates that adding one to 9 shows a result of ten but subtracting one from 10 shows a result of nine.

A number is created by adding two or more additional numbers or values. As an illustration, the outcome of adding 2 and 3 is 5.

2 + 3 = 5

Let's now look at the sum of 2 and 3 practically. What number of apples are there in total if we start with two apples in a basket and then add three more?

2 → 1 + 1

3 → 1 + 1 + 1

2 + 3 = 1 + 1 + 1 + 1 + 1

Counting each apple separately yields a total of 5 apples.

If we now count each apple, there are 5 total.

The ability to add to an existing value results in a rise.

To subtract is to take away another value to obtain the desired value.

For instance, 2 is the result when 3 is subtracted from 5.

5 - 3 = 2

How many apples are left in the basket if we believe there are 5 apples in it, and we take out 3 of them?

So, the answer is 2 apples.

5 - 3 = 1 + 1 + 1 + 1 + 1 - 1 + 1 + 1 = 2

Addition, Subtraction, Multiplication And Division

As we see above, the four major operations in mathematics are:

Addition
Subtraction
Multiplication
Division

Like addition and subtraction, multiplication and division are also inverse operations of each other.

Let us understand with an example,

If 3 is multiplied by 4,

3 x 4 = 12

So, the answer will be 12.

Now, if 12 is divided by 3,

12 ÷ 3 = 4.

Here, the answer is 4.

Addition And Subtraction For Classes 3 And 4

Grade 4 addition ranges from single two-digit addition with no regrouping. Let's understand more.

Mental Addition

Mental addition is the calculation (addition) of two different or the same values in mind (directly).

Some examples of mental addition are given below,

The sum of 2-digit numbers

13 + 24 = 37

Here, we can easily do a sum of 13 and 24 in mind in the given calculation.

The sum of three different values, two-digit numbers

10 + 12 + 14 = 36

Adding in Columns

For some additions, we need to do the sum of given values by putting them as Columns; let's see,

The sum of 3-digit numbers

123 + 345 =?

So, for the given addition, we have to put this in the column first

123

+ 345

468

Another example

456

+324

780

Here, the sum of the last digits 6 and 4 is 10. So, 0 is written as the answer and 1 will be added at the left-sided digit (5) of 6.

Now, we'll take the example of the addition of 3 three-digit numbers,

789

+ 687

+ 879

????

Here, the sum of the right-sided digit of each value is 9 + 7 + 9 = 25, so 5 will be written down, and 2 will be added at the next digit of 9.

789

+ 687

+ 879

So, 2 + 8 + 8 + 7 = 25. Now the same as above. 5 will be down, and 2 will be added to the next digit of 8, so at 7.

789

+ 687

+ 879

So, the sum of 2 + 7 + 6 + 8 = 23

789

+ 687

+ 879

2355

Here’s another example, sum of 456 + 689 =?

First, let’s write the sum in column form,

456

+689

???

Now, the sum of 6 + 9 = 15, 5 will be written down, and 1 is added to 5,

456

+689

The sum of 1 + 5 + 8 = 14, 4 will be written down, and 1 is added to 4.

456

+689

Next step, the sum of 1 + 4 + 6 = 11, so 11 will be written down.

456

+689

1145

So, the sum of 456 + 689 = 1145.

Now let's understand subtraction with examples,

Subtraction of 123 from 234

234

- 123

111

We’ll take some more examples to understand subtraction.

159

- 031

128

Let us understand how the subtraction mechanism works.

For example, 159 - 031,

First, we’ll write the given value in subtraction form,

159

- 031

???

Now, to find the answer, we’ll write numbers like this,

1 5 9

- 0 3 1

? ? ?

The first step is to subtract from the value's right side. So, we’ll do a subtraction of 9 and 1. So, 9 - 1 = 8.

1 5 9

- 0 3 1

? ? 8

As the next step, we’ll subtract the left side number of 9. So, for 5 and 3, 5 - 3 = 2.

1 5 9

- 0 3 1

? 2 8

Now, at the last step, the left-sided number of 5. So, 1 - 0 = 1.

1 5 9

- 0 3 1

1 2 8

This is how the subtraction mechanism works. Here we can see that this subtraction is done easily only when removing a small number from a bigger one.

Frequently Asked Questions (FAQs)

1. What do you mean by addition and subtraction?

The process in which we add or do a sum of two or more items or numbers of things is called addition. For example, Ayush has 12 bananas, and the prince has 1 banana. So, If the prince gives his banana to Ayush, the total number of bananas Ayush has will be 13. At the same time, the process in which we remove or minus or subtract things or items or numbers is called subtraction. For example, Ayush gives his 12 bananas to the prince. So, now Ayush has 0 bananas.

2. Is addition and subtraction inverse of each other?

Yes, addition and subtraction are inverses of each other. The addition is the process in which two values combine and form a new value. A small value is taken from a bigger value in the subtraction process.

3. Why does 5 + 3 equal 8, but 3 + 5 also equals 8?

This is due to the commutative property of addition. It states that the order of addends doesn't affect the sum. So, 5 + 3 and 3 + 5 both equal 8 because you're combining the same quantities, just in a different order.

4. Can you subtract a bigger number from a smaller one?

Yes, you can, but the result will be a negative number. For example, 3 - 5 = -2. This concept is important when working with integers and real-world scenarios involving debt or temperature below zero.

5. What's the difference between 15 - 7 and 7 - 15?

15 - 7 equals 8, while 7 - 15 equals -8. Subtraction is not commutative like addition. The order matters in subtraction, and changing it can result in a different answer, often with a change in sign.

6. What is regrouping in addition and subtraction?

Regrouping, also known as carrying or borrowing, is the process of exchanging values between place values. In addition, it's carrying a 1 to the next column when a sum exceeds 9. In subtraction, it's borrowing from the next column when you can't subtract the bottom number from the top in a particular place value.

7. What is the difference between addition and subtraction?

Addition is the process of combining two or more numbers to get a larger number (sum), while subtraction is the process of taking away one number from another to find the difference. Addition increases quantity, while subtraction decreases it.

8. What's the relationship between addition and subtraction?

Addition and subtraction are inverse operations. This means that one operation undoes the other. For example, if you add 5 to 3 and then subtract 5, you get back to 3. Understanding this relationship is crucial for solving equations and word problems.

9. How do you solve word problems involving addition and subtraction?

To solve word problems:

10. How do you add or subtract algebraic expressions?

To add or subtract algebraic expressions, combine like terms. Like terms have the same variables raised to the same powers. For example:

11. How do you add or subtract mixed numbers?

To add or subtract mixed numbers:

12. What's the concept of additive inverse?

The additive inverse of a number is the number that, when added to it, results in zero. For any number a, its additive inverse is -a. For example, the additive inverse of 5 is -5, because 5 + (-5) = 0. This concept is crucial in solving equations and understanding the nature of negative numbers.

13. How do you add or subtract fractions?

To add or subtract fractions, you need a common denominator. If the denominators are different, find the least common multiple (LCM) and adjust the fractions accordingly. Then, add or subtract the numerators while keeping the denominator the same. For example:

14. How do you add or subtract when there are decimals involved?

When adding or subtracting decimals, align the decimal points vertically. Then, perform the operation as usual, keeping the decimal point in the same position in your answer. For example:

15. Why do we start adding or subtracting from the right side?

We start from the right (ones place) and move left because it allows us to handle carrying or borrowing efficiently. This method ensures we deal with each place value systematically, making the process more organized and less prone to errors.

16. What's the difference between 3 + 4 and 3 - (-4)?

3 + 4 and 3 - (-4) both equal 7, but they represent different concepts. 3 + 4 is simple addition, while 3 - (-4) involves subtracting a negative number, which is equivalent to adding its positive counterpart. Understanding this helps in working with integers and algebraic expressions.

17. How do you check if your subtraction is correct?

To check subtraction, add the difference (answer) to the number you subtracted. If your subtraction was correct, this sum should equal the original number you subtracted from. For example, to check 15 - 7 = 8, add 8 + 7. If it equals 15, your subtraction was correct.

18. Is there an identity element for subtraction?

Unlike addition, subtraction doesn't have an identity element. There's no number that, when subtracted from any other number, always leaves that number unchanged. This is one key difference between addition and subtraction operations.

19. How do you add or subtract numbers represented in scientific notation?

To add or subtract numbers in scientific notation:

20. How do you handle addition and subtraction with signed zeros in computing?

In computing, signed zeros (+0 and -0) can behave differently:

21. How do addition and subtraction relate to the concept of vectors?

In vector mathematics:

22. What's the identity element for addition?

The identity element for addition is zero (0). Adding zero to any number doesn't change the number's value. For example, 5 + 0 = 5. This concept is crucial in understanding more advanced mathematical operations and proofs.

23. How do you add or subtract negative numbers?

When adding negative numbers, think of it as subtraction. When subtracting negative numbers, think of it as addition. For example:

24. What's the difference between 5 - 3 and -(3 - 5)?

5 - 3 equals 2, while -(3 - 5) also equals 2. The second expression involves the concept of negation. 3 - 5 equals -2, and negating -2 gives 2. This illustrates how parentheses and negation can affect the outcome of arithmetic operations.

25. What's the associative property of addition?

The associative property of addition states that the grouping of addends doesn't affect the sum. For example, (2 + 3) + 4 = 2 + (3 + 4). This property is useful in mental math and understanding more complex mathematical concepts.

26. Does subtraction have the associative property?

No, subtraction is not associative. The order of operations matters in subtraction. For example, (10 - 5) - 3 ≠ 10 - (5 - 3). The first equals 2, while the second equals 8. This is why parentheses are important in expressions involving multiple subtractions.

27. What's the difference between 2 - 3 and 3 - 2?

2 - 3 equals -1, while 3 - 2 equals 1. This illustrates that subtraction is not commutative. Changing the order of numbers in subtraction changes the result, often including a change in sign. Understanding this helps in solving equations and word problems.

28. How do you add or subtract numbers in different bases?

To add or subtract numbers in different bases:

29. What's the difference between arithmetic and algebraic subtraction?

Arithmetic subtraction deals with specific numbers, while algebraic subtraction involves variables and expressions. In algebra, subtraction is often viewed as adding the opposite. For example, 5 - 3 in arithmetic is 2, while x - 3 in algebra is understood as x + (-3). This perspective helps in solving equations and manipulating expressions.

30. How do you add or subtract very large numbers?

For very large numbers:

31. What's the role of zero in addition and subtraction?

Zero plays several roles:

32. What's the connection between addition/subtraction and the number line?

On a number line:

33. How do you mentally add or subtract numbers ending in zeros?

For numbers ending in zeros:

34. What's the difference between additive and multiplicative thinking?

Additive thinking involves combining or separating quantities (e.g., 5 + 3 or 8 - 2). Multiplicative thinking involves scaling or repeated addition (e.g., 3 × 4 or 12 ÷ 3). Understanding the shift from additive to multiplicative thinking is crucial for grasping concepts like ratios, proportions, and algebraic relationships.

35. How do you add or subtract time?

When adding or subtracting time:

36. What's the relationship between addition/subtraction and counting?

Addition can be seen as forward counting, while subtraction is backward counting. For example, 5 + 3 can be solved by counting forward 3 steps from 5. Similarly, 8 - 3 can be solved by counting backward 3 steps from 8. This connection helps build a foundational understanding of arithmetic operations.

37. How do rounding and estimation relate to addition and subtraction?

Rounding and estimation are useful for:

38. What's the concept of additive decomposition?

Additive decomposition involves breaking numbers into parts that are easier to work with. For example, 8 can be decomposed as 5 + 3 or 4 + 4. This concept is crucial for mental math strategies and understanding place value. It's also a foundation for algebraic thinking and more advanced number theory.

39. How do you add or subtract numbers with different units?

To add or subtract numbers with different units:

40. What's the connection between addition/subtraction and comparison?

Addition and subtraction are fundamental to comparison:

41. What's the role of addition and subtraction in solving equations?

Addition and subtraction are key in solving equations:

42. How do addition and subtraction relate to the concept of distance?

Distance on a number line is related to addition and subtraction:

43. What's the difference between arithmetic and algebraic addition/subtraction?

Arithmetic addition/subtraction deals with specific numbers, while algebraic addition/subtraction involves variables and expressions:

44. How do addition and subtraction relate to the concept of net change?

Net change is the overall result after a series of additions and subtractions: