Addition and subtraction are the two primary arithmetic operations where we learn to add and subtract two or more numbers or any mathematical values. The other two basic math operations are multiplication and division. The symbol to represent addition is ‘+’ (plus sign) and subtraction is ‘-’ (minus sign).
Both addition and subtraction are inverse operations of each other. For example, if 9 + 1 = 10, then 10 – 1 = 9. That shows if 1 is added to 9 then the result is 10, whereas if 1 is subtracted from 10, then the result is 9.
What is Addition?
Addition means summing up two or more numbers or values to get another number. For example, if we add 2 and 3, we get 5 as the result.
2 + 3 = 5
Now, let us understand the sum of 2 and 3 practically. Suppose, we have 2 apples in a basket and 3 more apples are added in the same basket, so how many apples are there altogether?
2 → 1 + 1
3 → 1 + 1 + 1
2 + 3 = 1 + 1 + 1 + 1 + 1
Now if we count each apple, then it is equal to 5.
The property of addition is to increase the value by adding another value to it.
What is Subtraction?
Subtraction means reducing a value from another value to get the required value.
For example, subtracting 3 from 5 gives 2 as the answer.
5 – 3 = 2
Now, if we imagine, there are 5 apples in a basket and we take out 3 apples from the basket, then how many apples are left?
The answer is 2 apples.
5 – 3 = 1 + 1 + 1 + 1 + 1 – 1 – 1 – 1 = 2
Addition, Subtraction, Multiplication and Division
As we mentioned earlier, the four major operations in mathematics are:
- Addition
- Subtraction
- Multiplication
- Division
Multiplication and division are also the inverse operations of each other.
- 2 multiplied by 3 is 6
- 6 divided by 3 is 2
Also, the multiplication of numbers displays the repeated addition.
- 2 x 4 = 8
- 2 + 2 + 2 + 2 = 8
Rules
The rules to add and subtract numbers are given below:
- Addition of two positive numbers is always positive
- Addition of two negative numbers is always negative
- Subtraction of two positive numbers can be either positive or negative
- Subtraction of two negative numbers can be either positive or negative
| Positive + Positive | Addition (Sign will be Positive) | 3 + 4 = 7 |
| Negative + Negative | Addition (Sign will be negative) | – 3 + (-4) = -7 |
| Positive + Negative | Subtraction (Sign of greater number) | 3 + (-4) = -1 |
| Positive – Negative | Addition (Sign will be Positive) | 3 – (-4) = 3 + 4 = 7 |
| Negative – Positive | Addition (Sign will be negative) | -3 – (4) = -7 |
For One Digit
One digit numbers are all the single-digit integers, i.e.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| -1 | -2 | -3 | -4 | -5 | -6 | -7 | -8 | -9 |
Addition of one-digit numbers
If we add any two one-digit positive numbers, then the result is either a single-digit or double-digit number.
1+7 = 8
8 + 7 = 15
Subtraction of one-digit numbers
Subtraction of any two one-digit positive numbers will always result in a single-digit number.
8 – 5 = 3
For Two-digit numbers
We can take two-digit positive and negative numbers to add and subtract.
Addition of two-digit positive numbers may result in a 3-digit value but subtraction of two-digit positive numbers will not result in a three-digit value. A few examples are:
- 22 + 13 = 35
- 99 + 10 = 109
- 99 – 10 = 89
- 80 – 15 = 65
For Three-digit numbers
In the case of three-digit positive numbers, the same rules apply for addition and subtraction that are similar to one-digit and two-digit numbers.
- 100+101 = 201
- 999 + 100 = 1099
- 100 – 1 = 99
- 999 – 100 = 899
Addition and subtraction of Fractions
Fractions are the value in Maths, that represents part of a whole. Examples of fractions are ½, ⅓, ¼, ¾, ⅔, etc.
Adding fractions:
½ + ½ = 1
It shows if two halves are added together, then it results in a whole.
Subtracting fractions:
¾ – ¼ = 2/4 = ½
Addition and subtraction with regrouping
Regrouping, in addition, is done if the sum of numbers in the unit place will result in a number more than 9, and the additional digit is carried forward to the next value at ten’s place and gets added. Let us see an example to understand.
Example: Add 248 and 175
21 41 8
+ 1 7 5
————
4 2 3
————
In the above example, 8 + 5 = 13, thus we kept 3 at the unit place of the answer, and 1 is carried forward and added to 4 and 7. Now, 1+4+7 = 12. So, 2 is kept and 1 is again carried forward to add with 2 and 1. 1+2+1 = 4.
Regrouping for subtraction:
Subtract 182 from 427.
4 2 7
– 1 8 2
————–
2 4 5
————–
In the above example, at the unit place, 7 – 2 gives 5, but at ten’s place, we need to borrow 1 to group 2 as 12 and then subtract 8 from it. So, 12 – 8 = 4. Since 1 is taken from 4 at a hundred’s place, thus we are left with 4 -1 = 3. Now subtract 3 – 1 = 2.
Worksheets
Students of Class 2, Class 3, Class 4 and Class 5 can practise the addition and subtraction of numbers with the help of these worksheets. These questions will help them to brush up on their skills in this concept.
1. 6 – (-9) = ?
2. 10 – (10) = ?
3. 10 – (8) = ?
4. 34 – (-9) = ?
5. 73 – (88) = ?
6. 78+ (-12) = ?
7. 68 + (-56) = ?
8. 36 + (9) = ?
9. 94 + (-99) = ?
10: (-63) + (0) = ?
Word problems
The word problems based on addition and subtraction are given below along with solutions.
Q.1: Ritu has 7 balloons and her friend Seema has 5 balloons. How many more balloons does Ritu have than her friend?
Solution: Given that we have 7 balloons and our friend has 5 balloons.
7 – 5 = 2
Thus, Ritu has 2 more balloons than her friend.
Q.2: 114 birds were sitting on a tree. 21 more birds flew up to the tree. How many birds were there altogether on the tree?
Solution: Given that there are 114 birds on a tree.
21 more birds flew up to the tree.
114 + 21 = 135
There were 135 birds on the tree.
