Unlocking Numbers: The Top 100 Math Tricks You Need to Know!

Austin Wright
Austin Wright - Contributor
16 Min Read


Mathematics can often seem daunting, but with the right tricks and techniques, it can be simplified and even made fun! This comprehensive article features the top 100 math tricks that everyone should know. Whether you’re a student, a teacher, or just someone looking to sharpen their math skills, these tricks will help you solve problems faster and more efficiently. Let’s dive in!


1. Multiplying by 9 Using Your Fingers

To multiply any number by 9, use your fingers. Hold up both hands, and for 9 times 3, fold down your third finger. The number of fingers to the left (2) will be the tens place, and to the right (7) will be the ones place. Thus, 9 x 3 = 27.

2. The 11 Rule for Multiplication

To multiply two-digit numbers by 11, simply add the two digits of the number and place the result in-between them. For example, 34 x 11 = 3 (3+4) 4 = 374. If the sum exceeds 9, carry over the one.

3. Divisibility Rules for 3

You can determine if a number is divisible by 3 if the sum of its digits is divisible by 3. For example, 123: 1 + 2 + 3 = 6, which is divisible by 3.

4. Squaring Any Number Ending in 5

To square a two-digit number ending in 5, multiply the first digit by itself plus one, then append 25. For example, 75² = 7 × 8 = 56 → 5625.

5. Finding Percentages Quickly

To quickly find 10% of a number, just divide it by 10. For 25%, multiply that by 2. For example, 10% of 250 is 25, and 25% is 62.5.

6. Multiplying by 5

To multiply a number by 5, first, divide it by 2, then multiply the result by 10. For instance, 6 x 5 → (6 ÷ 2) x 10 = 30.

7. The Rule of 72

To estimate how long it will take for an investment to double, divide 72 by the interest rate. For example, at an 8% interest rate, it will take about 9 years (72/8).

8. Timetable of Squares

Recognize the pattern of squares for numbers 1-20. For instance, 1²=1, 2²=4, 3²=9… up to 20²=400. This helps in mental calculations.

9. Multiplication by 4

To multiply a number by 4, simply double the number twice. For example, to compute 4 x 7, double 7 to get 14, then double 14 to get 28.

10. Adding and Subtracting Fractions

When adding fractions, ensure they have a common denominator. An easy way is to cross-multiply and add/subtract the products.

11. Using a Number Line for Addition and Subtraction

Visualizing numbers on a number line can simplify addition and subtraction, particularly for younger learners.

12. Algebraic FOIL Method for Binomials

The FOIL method (First, Outside, Inside, Last) helps in multiplying binomials. For example, (x + 2)(x + 3) becomes x² + 3x + 2x + 6 = x² + 5x + 6.

13. The Distributive Property

This property states that a(b+c) = ab + ac. It simplifies calculations significantly.

14. Complement Addition

For numbers that add up to ten, make the calculations simpler. For instance, 8 + 2 = 10.

15. Finding Square Roots with Estimation

To estimate the square root of a number, find two perfect squares it lies between. For example, √50 is between √49 (7) and √64 (8).

16. Divisibility Rules for 5

A number is divisible by 5 if its last digit is either a 0 or 5. It’s as simple as checking the last digit.

17. Using Symmetry for Shapes

Symmetry in geometry can help in calculating area and perimeter, particularly for quadrilaterals.

18. Pythagorean Theorem (a² + b² = c²)

This theorem helps in calculating the length of the sides of a right triangle.

19. Quickly Identify Perfect Squares

Memorizing perfect squares up to 20 can speed up calculations. For instance, 6² = 36 and 12² = 144.

20. Calculate Days in Different Months

Remember that February has 28 days (29 in leap years), while all others can be remembered with the rhyme: "30 days hath September…"

21. The 5-Percent Trick

To find 5% of a number, divide it by 20. For instance, 100 ÷ 20 = 5.

22. Visualizing Algebra with Diagrams

Using diagrams to visualize algebraic equations can often make solving them easier.

23. Rounding Rules

When rounding numbers, if the digit to be dropped is 5 or greater, round up; otherwise, round down.

24. Mind Mapping for Problem Solving

For complicated word problems, drawing mind maps can help in visualizing and solving them systematically.

25. What is a Factor Tree?

Creating a factor tree is a helpful method for identifying prime factors of a number.

26. The Power of Zero

Understanding how any number multiplied by zero equals zero is fundamental to mathematics.

27. The Golden Ratio (Φ)

This ratio, approximately 1.618, appears in various aspects of art and nature.

28. Using Exponents

Knowing how to use exponents can simplify large calculations. For instance, 10² = 100.

29. The Magic of Pi (π)

Realizing that π is approximately 3.14 helps in calculations involving circles.

30. Graphing Basics

Understanding coordinate planes and how to plot points is crucial for graphing functions.

31. Understanding Ratios

Ratios can help simplify comparisons between two quantities effectively.

32. The Fibonacci Sequence

Recognizing this sequence and its application in nature can help in identifying patterns.

33. Complementary Angles

Two angles are complementary if their sum equals 90 degrees, a useful concept in geometry.

34. Estimation Techniques

Round numbers to estimate results quickly.

35. The Equation of a Line (y = mx + b)

Understanding slope-intercept form provides a clear way to represent linear equations graphically.

36. Decimal to Fraction Conversion

To convert decimals to fractions, place the decimal over its place value, then simplify.

37. Finding the Least Common Multiple (LCM)

The LCM helps with adding fractions with different denominators.

38. Understanding Population Growth

Using exponential growth formulas can effectively model population increases.

39. The Basic Addition and Subtraction Tricks

Flipping numbers can often double-check addition and subtraction results.

40. Multiplying by 1.5

To multiply a number by 1.5, first multiply it by 3 and then divide by 2.

41. Proportions in Word Problems

Understanding proportions can make solving ratios in word problems much easier.

42. Percent Change Calculation

To find percent change, subtract the old value from the new, divide by the old value, and multiply by 100.

43. Graphing Linear Equations

Understanding the x and y-intercepts can make graphing linear equations much simpler.

44. The Order of Operations (PEMDAS)

Remembering Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction helps in problem-solving.

45. Finding Averages

Calculate averages by adding together all numbers in a set and dividing by the total count of numbers.

46. Integer Operations

Understanding the rules of integers, particularly with positive and negative numbers is essential for basic arithmetic.

47. The Slope of a Line

The slope formula (rise/run) is crucial for understanding how steep a line is in graphing.

48. The Cartesian Coordinate System

Familiarizing yourself with X and Y axis helps in plotting points and understanding relations.

49. Understanding Absolute Value

Memorizing the concept of absolute value — the distance of a number from zero — is key in algebra.

50. Using Google Calculator or Online Resources

Embrace technology, like Google’s built-in calculator for quick computations.

51. Quickly Solve 3-Digit Multiplications

Break down the multiplication using the distributive property to simplify the process.

52. Calculating Angles in Triangles

The sum of angles in any triangle equals 180 degrees, a useful principle in geometry.

53. Understanding the Quadratic Formula

The quadratic formula (x = [-b ± √(b² – 4ac)] / 2a) is essential for solving quadratic equations.

54. Understanding Probability

From the basics of probability to more complex calculations, knowing how to calculate chance is essential.

55. Drawing Circles with a Compass

This technique teaches precision and can simplify geometry problems related to circles.

56. Using Percentages Wisely

Understanding how to convert percentages into decimals can simplify calculations.

57. Understanding Inequalities

The symbols >, <, ≥, and ≤ are essential tools in algebra and can simplify solving equations.

58. Basic Set Theory

Understanding sets and subsets aids in organizing information.

59. Using Venn Diagrams

These diagrams help visualize and solve problems involving multiple sets.

60. Basic Economic Formulas

Familiarizing yourself with basic economic concepts, like supply and demand curves, can help in business math.

61. Making Use of Statistics

Statistical methods can simplify data analysis and trends.

62. Average Speed Calculations

It’s important to understand how to calculate average speed, particularly in physics problems.

63. Geometric Mean

Understanding and calculating the geometric mean is vital in statistics and averages.

64. Quick Currency Conversion

Using online calculators for currency conversion can save time and ensure accuracy.

65. Trigonometry Basics

Familiarize yourself with sine, cosine, and tangent for solving triangles.

66. Understanding Limits

Basic limit concepts are vital in calculus.

67. Constructing Palindromic Numbers

Recognizing and creating palindromic numbers can be fun and enlightening.

68. Calculating Volume

Familiarizing yourself with volume formulas for different shapes helps in various real-world applications.

69. Recognizing Patterns in Numbers

Learning to recognize mathematical patterns aids in problem-solving.

70. Calendar Calculations

Understanding how to calculate days between dates using various approaches is handy.

71. Graph of Polynomials

Graphing polynomials can help visualize solutions and roots.

72. Understanding Symmetry in Algebraic Functions

Symmetry in functions simplifies calculations and graphing.

73. Mastering the Unit Circle

Understanding the unit circle is crucial for trigonometry.

74. Proving Theorems

Practicing theorem proofs can significantly enhance understanding of mathematical structures.

75. Creating Backwards Problems

Working backward can sometimes simplify complex problems.

76. Implementation of Array Models

Visualizing multiplication through array models can aid understanding.

77. Understanding Limits in Calculus

Knowing limit definitions eases calculus studies.

78. Order of Operations Reminders

Regular practice with the order of operations ensures mastery.

79. Advanced Geometry

Diving deep into geometric principles opens new doors in math exploration.

80. Using Graphing Calculators

Utilizing technology can help simplify graphing calculations.

81. Mental Math Techniques

Improving mental math can enhance problem-solving speed.

82. The Power of Grouping

Grouping numbers can simplify addition and subtraction tasks.

83. Self-Reflection in Math Studies

Self-assessment can create aware learners in math.

84. Different Types of Angles

Knowing the types of angles enhances geometry comprehension.

85. Perfect Square Factorization

Learning how to factor perfect squares simplifies many problems.

86. Working with Polynomials

Rounding out polynomial skills can enhance algebraic understanding.

87. Tackling Complex Word Problems

Using systematic approaches can simplify these challenges.

88. Understanding Completion of the Square

This technique is crucial for mastering quadratic equations.

89. Dividing by 10, 100, 1000

Simply move the decimal point left to divide by 10, 100, or 1000.

90. Mastering Fractions

Deepening the understanding of fractions allows for easier calculations.

91. Using Mathematical Properties

Utilizing properties such as associative and commutative can streamline calculations.

92. Building Functions with Technology

Utilizing software applications to visualize functions provides new insights.

93. Executing Data Analysis

Understanding basic data analysis techniques aids in statistics.

94. Graphing Multivariable Functions

Exploring 3D functions can enhance graphing skills.

95. Explorative Learning in Math

Encouraging exploration can ignite a love for mathematics.

96. Hands-On Math Activities

Incorporating hands-on activities can make math learning engaging.

97. Understanding the Area Under Curves

Knowing how to compute areas under curves deepens calculus knowledge.

98. Combining Mathematical Techniques

Blending various techniques can promote versatility in problem-solving.

99. Utilizing Online Math Resources

Numerous resources exist online for further exploration of topics.

100. Embracing a Positive Math Mindset

A positive attitude towards math can lead to improved understanding and performance.


Conclusion

With these top 100 math tricks at your disposal, you’re well-equipped to tackle any mathematical challenge! From techniques aiding rapid calculations to principles that deepen your understanding, these tricks provide the foundational tools for both academic success and practical applications in everyday life. Remember, practice is key—so continue exploring, learning, and embracing the magic of mathematics!

Resources

Feel free to dive deeper into each trick, and discover the fun and intriguing world of mathematics!

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Austin is a tech entrepreneur and product leader with a passion for building AI-driven tools that make life easier, smarter, and more efficient. He is the founder behind several innovative platforms, including JobFly.io, InstagramDMs.com, and IPFind, and she runs AllThePicks.com, a leading destination for data-powered sports betting advice. Austin is also the driving force behind Smodin.io, one of the most trusted AI tools for students and educators worldwide. On TheBest100.ai, Austin curates high-impact lists across tech, education, and productivity—making it easier for people to discover the tools and insights that actually matter.
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