Mental Maths Tricks for Fast Calculation in today’s fast-paced world, being able to perform quick mental calculations can save time and make daily life more efficient.
Mental Maths Tricks for Fast Calculation
Fortunately, there are numerous mental maths tricks and techniques that can help you compute complex calculations in the blink of an eye.
In this article, we will explore some of these tricks and provide you with valuable tools to enhance your mental calculation abilities.
The Power of Number Approximation
One effective mental maths technique is approximation. Instead of aiming for precise calculations, you can round numbers to the nearest convenient value to simplify the process.
For instance, if you need to multiply 38 by 7, you can approximate 38 to 40 and 7 to 10.
Multiplying 40 by 10 gives you 400, and since you rounded up, you need to subtract the error. Therefore, the result is 400 – 2 = 398. This technique is particularly useful when working with large numbers or complex equations.
Breaking Down Numbers
Breaking down numbers into more manageable parts can significantly speed up mental calculations.
For example, when multiplying two-digit numbers, you can split them into their tens and units digits.
Let’s say you need to multiply 47 by 38. Break it down into (40 + 7) multiplied by (30 + 8).
This simplifies the calculation to four smaller multiplications: 40 multiplied by 30, 40 multiplied by 8, 7 multiplied by 30, and 7 multiplied by 8. Add the results together to get the final answer: 1,790.
The Magic of Number Doubling and Halving
Doubling and halving numbers is a handy trick to perform mental calculations faster.
When multiplying by 2, simply double the number. Conversely, when dividing by 2, halve the number. For example, if you need to multiply 65 by 4, double 65 to get 130 and double it again to get 260.
If you need to divide 96 by 2, halve 96 to get 48. This method is especially useful when dealing with fractions and percentages.
Utilizing the Power of 9
Multiplying numbers by 9 can be simplified by using a special trick.
To multiply a number by 9, subtract 1 from the number, and the result will be the tens digit. The units digit is obtained by subtracting the tens digit from 9.
For example, to multiply 6 by 9, subtract 1 from 6 to get 5 (the tens digit) and subtract 5 from 9 to get 4 (the units digit). The final result is 54.
Cross Multiplication for Fractions
When comparing fractions or solving proportion problems, cross multiplication can save you time.
Let’s say you want to compare the fractions 3/5 and 2/3 to determine which is larger. Multiply 3 by 3 and 5 by 2 to get 9 and 10, respectively. T
he fraction with the larger product is the larger fraction, so in this case, 2/3 is larger than 3/5. This method simplifies the process of comparing and solving fraction-related calculations.
Mental Maths Tricks for Fast Calculation
Mastering mental maths tricks can greatly improve your ability to perform calculations quickly and accurately.
The techniques mentioned above, such as number approximation, breaking down numbers, doubling and halving, utilizing the power of 9, and cross multiplication, can become invaluable tools in your mental maths toolkit.
Practice these tricks regularly, and you’ll notice a significant improvement in your mental calculation speed and efficiency. With a little dedication and regular practice, you’ll become a mental maths whiz in no time!
Squaring Numbers Ending in 5
To square a number ending in 5, multiply the digit before 5 by its successor and append 25 to the result. For example, to square 35, multiply 3 by 4 (which gives 12) and append 25, resulting in 1225.
Multiplying by 11
To multiply a two-digit number by 11, add the digits and place the sum between the original digits. If the sum is greater than 9, carry over the tens digit.
For instance, to multiply 32 by 11, add 3 and 2 to get 5 and place it between the original digits, giving you 352.
Percentage Calculations
Finding percentages mentally can be simplified by converting percentages into fractions or decimals.
For example, to calculate 30% of 80, mentally convert 30% to the decimal form 0.3 and multiply it by 80, resulting in 24.
Similarly, to find 15% of 200, convert 15% to the decimal form 0.15 and multiply it by 200 to get 30.
Divisibility Rules
Knowing divisibility rules can help you quickly determine if a number is divisible by another number without performing the division.
For example, a number is divisible by 2 if the last digit is even (0, 2, 4, 6, or 8), and a number is divisible by 3 if the sum of its digits is divisible by 3.
These rules can save time when determining divisibility without using a calculator.
Estimation Techniques
Estimation can be a powerful tool when you need a quick answer or want to check the reasonableness of your calculations.
Round numbers to their nearest convenient values and perform calculations using the rounded figures. This method can help you quickly assess if your answer is in the right ballpark.
Mental Subtraction
Subtracting numbers mentally can be simplified by using the concept of complements.
If you need to subtract a number, find its complement that adds up to the next higher multiple of 10 or 100.
Subtract the complement from the higher multiple, and then subtract the remaining difference from the complement.
This technique is especially useful when subtracting large numbers.
Fibonacci Sequence
The Fibonacci sequence (0, 1, 1, 2, 3, 5, 8, 13, …) is a series of numbers where each number is the sum of the two preceding ones. This sequence can be handy for mental calculations involving ratios, proportions, and even estimating distances or measurements.
Mental Maths Tricks for Fast Calculation
Remember, regular practice is the key to mastering these mental maths tricks. With time and dedication, you’ll be amazed at how quickly and accurately you can perform complex calculations mentally, making your daily life more efficient and your mathematical abilities more impressive.
