Class 1 Maths Formulas – All Important Formulas, Rules and Examples
Class 1 Maths Formulas: Mathematics is an important subject for young learners. In Class 1, students learn counting, numbers, addition, subtraction, shapes, measurements, time, money and patterns.
This article covers important maths formulas, basic rules and examples for Class 1 students following NCERT-level mathematics.
1. Counting Numbers
Counting numbers help us count objects such as books, pencils, fruits and toys.
Examples:
- Number before 5 = 4
- Number after 5 = 6
- Number between 3 and 5 = 4
- Smallest counting number = 1
2. Number Names
Number names are the words used to read and write numbers.
| Number | Number Name |
|---|---|
| 1 | One |
| 2 | Two |
| 3 | Three |
| 4 | Four |
| 5 | Five |
| 6 | Six |
| 7 | Seven |
| 8 | Eight |
| 9 | Nine |
| 10 | Ten |
| 11 | Eleven |
| 12 | Twelve |
| 13 | Thirteen |
| 14 | Fourteen |
| 15 | Fifteen |
| 16 | Sixteen |
| 17 | Seventeen |
| 18 | Eighteen |
| 19 | Nineteen |
| 20 | Twenty |
3. Place Value
Place value tells us the value of a digit according to its position in a number.
- Ones place: 1 one = 1
- Tens place: 1 ten = 10 ones
- 2 is in the tens place: 2 × 10 = 20
- 5 is in the ones place: 5 × 1 = 5
4. Comparison of Numbers
We use these symbols to compare numbers.
- Greater than: >
- Less than: <
- Equal to: =
8 > 5
3 < 7
6 = 6
Rule: When comparing two numbers, the number that comes later in counting is greater.
5. Ascending and Descending Order
Ascending Order
Arranging numbers from smallest to largest.
Descending Order
Arranging numbers from largest to smallest.
6. Addition Formula
Addition means putting two or more groups together.
a + b = c
2 + 3 = 5
4 + 5 = 9
6 + 2 = 8
10 + 5 = 15
Important Addition Rules
- Adding zero does not change a number: 5 + 0 = 5.
- Changing the order of numbers does not change the sum: 2 + 3 = 3 + 2.
- Adding one gives the next number: 6 + 1 = 7.
7. Subtraction Formula
Subtraction means taking away one number from another.
a − b = c
5 − 2 = 3
9 − 4 = 5
8 − 3 = 5
10 − 0 = 10
Important Subtraction Rules
- Subtracting zero does not change a number: 7 − 0 = 7.
- Subtracting a number from itself gives zero: 5 − 5 = 0.
- Subtraction is not generally reversible: 5 − 2 is not equal to 2 − 5.
8. Relationship Between Addition and Subtraction
Addition and subtraction are related mathematical operations.
If 3 + 2 = 5, then:
- 5 − 2 = 3
- 5 − 3 = 2
Rule: Addition can help us check subtraction, and subtraction can help us check addition.
9. Zero and One Rules
| Rule | Example |
|---|---|
| Number + 0 = Number | 8 + 0 = 8 |
| Number − 0 = Number | 8 − 0 = 8 |
| Number − Same Number = 0 | 8 − 8 = 0 |
| Number + 1 = Next Number | 8 + 1 = 9 |
| Number − 1 = Previous Number | 8 − 1 = 7 |
10. Even and Odd Numbers
Even numbers: Numbers whose objects can be arranged in pairs without leaving one object alone.
Examples: 2, 4, 6, 8, 10, 12.
Odd numbers: Numbers whose objects leave one object without a pair when grouped in twos.
Examples: 1, 3, 5, 7, 9, 11.
11. Basic Multiplication Idea
Multiplication is repeated addition. This is an introductory concept for young learners.
2 + 2 = 4: Two groups of 2 make 4.
3 + 3 = 6: Two groups of 3 make 6.
2 + 2 + 2 = 6: Three groups of 2 make 6.
12. Basic Division Idea
Division means sharing objects equally into groups.
6 ÷ 2 = 3
If 6 chocolates are shared equally between 2 children, each child receives 3 chocolates.
13. Basic Shapes
Shapes help children identify and describe objects around them.
| Shape | Property | Example |
|---|---|---|
| Circle | Round shape | Coin |
| Triangle | 3 sides | Triangular sign |
| Square | 4 equal sides | Square tile |
| Rectangle | 4 sides; opposite sides equal | Book cover |
| Sphere | Ball-shaped | Football |
| Cube | 6 square faces | Dice |
| Cylinder | Two circular ends and one curved surface | Can |
| Cone | One circular base and a pointed top | Ice-cream cone |
14. Basic Measurement
Measurement helps us compare length, height, weight and capacity.
- Length: Longer and shorter.
- Height: Taller and shorter.
- Weight: Heavier and lighter.
- Capacity: Holds more and holds less.
A pencil is shorter than a ruler.
A school bag is usually heavier than an eraser.
A bucket holds more water than a cup.
15. Time and Calendar
Children learn about days, months and daily activities.
1 day = 24 hours
1 year = 12 months
Days of the Week
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday.
Months of the Year
January, February, March, April, May, June, July, August, September, October, November and December.
Common parts of the day are morning, afternoon, evening and night.
16. Money
Money is used to buy and sell things. In India, we use rupees and paise.
₹5 + ₹2 = ₹7
₹10 − ₹4 = ₹6
₹2 + ₹2 + ₹2 = ₹6
Children should learn to identify coins and notes used in everyday life.
17. Number and Shape Patterns
Patterns are repeated arrangements of numbers, shapes or objects.
1, 2, 1, 2, 1, 2, ...
2, 4, 6, 8, ...
Circle, square, circle, square, ...
Rule: Look for what repeats or changes to find the next item.
18. Position and Directions
Children learn where objects are located.
- Up and down
- Left and right
- Inside and outside
- Above and below
- Near and far
- Before and after
19. Important Class 1 Maths Rules at a Glance
| Topic | Rule or Formula |
|---|---|
| Addition | Number + Number = Sum |
| Subtraction | Number − Number = Difference |
| Place value | Digit × Value of Its Place |
| Addition with zero | Number + 0 = Number |
| Subtraction with zero | Number − 0 = Number |
| Same number subtraction | Number − Same Number = 0 |
| Next number | Number + 1 |
| Previous number | Number − 1 |
| Equal groups | Repeated addition |
| Equal sharing | Total ÷ Number of Groups |
| Week | 7 days |
| Year | 12 months |
| Rupee | ₹1 = 100 paise |
20. Class 1 Maths Practice Questions
- What number comes after 9?
- What number comes before 15?
- Solve: 4 + 3 = ?
- Solve: 8 − 5 = ?
- What is the place value of 2 in 24?
- Which number is greater: 7 or 5?
- Name a shape with three sides.
- How many days are there in one week?
- How many paise make one rupee?
- What comes next: 2, 4, 6, 8, __?
Answers to Practice Questions
- 10
- 14
- 7
- 3
- 20
- 7
- Triangle
- 7 days
- 100 paise
- 10
Conclusion
Class 1 Mathematics builds the foundation for future learning. Students should practise counting, number names, place value, addition, subtraction, shapes, measurement, time, money and patterns regularly.
This collection of basic formulas, rules and examples is a useful revision guide for Class 1 students and parents. The exact topics covered may vary by NCERT textbook edition and school syllabus.
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