“Speed Techniques for Lightning-Fast Calculations”

Welcome back to our blog series on Mastering Numerical Reasoning for competitive exams! Today, we delve into the fascinating world of mental math and uncover speed techniques for lightning-fast calculations.

The Power of Mental Math

Mental math is the ability to perform mathematical calculations quickly and accurately without the use of external aids such as calculators or pen and paper. It not only enhances computational speed but also sharpens logical thinking and problem-solving skills, boosts confidence, and saves precious time during exams. It is the key to succeed in any competitive exams, as time is the crucial part of these exams. Let’s unlock the secrets to mastering mental math techniques.

Quick Mental Math Techniques

Let’s explore some essential mental math techniques for multiplication, division, addition, and subtraction:

1. Multiplication – To Multiply Any Number By 5:

• Step I): Divide the number by 2: This step is equivalent to finding half of the number.
• Step II): Add a zero: After dividing by 2, simply add a zero at the end of the result.

Let’s illustrate this with an example:

If you want to multiply 68 by 5 using the 5’s multiplication trick:

• Divide 68 by 2: 68 ÷ 2 = 34
• Multiply by 10: 39 x 10 = 340 ( simply put 0 at the end)

Thus, 68 multiplied by 5 is 340.

This trick is particularly useful for quick mental calculations and can save a lot of time during exams or daily calculations.

2. Division – To Divide Any Number By 5:

• Step I): Double the number: Multiply the given number by 2.
• Step II): Move the decimal point: Shift the decimal point one place to the left in the result, or in simple words, divide by 10.

Let’s walk through an example to illustrate this division trick:

If you want to divide 160 by 5 using the 5’s division trick:

Double 160: 60 x 2 = 320

Move the decimal point: 320 becomes 32.0 after shifting the decimal point one place to the left.

So, 160 divided by 5 equals 32 using this trick.

3. Addition – Give-And-Take Techniques

• Utilize give-and-take techniques.
• For example, when adding 47 + 29, give 1 to 29 to convert it into 30 (29+1=30) and take away 1 from 47 converting it to 46 (47 – 1 =46).
• Now easily add 30 + 46= 76.
• Practice mental addition with two-digit and three-digit numbers to improve speed.

4. Subtraction – All From Nine Last From Ten

• Use the concept of all from nine last from ten to subtract numbers from its base numbers which are powers of 10 i.e., 100, 1000, 10000, etc

• Step I) Subtract each digit of the number from 9: For each digit in the number you’re subtracting, subtract that digit from 9.
• Step II) Subtract the last digit from 10: After subtracting each digit from 9, subtract the last digit of the number from 10.

Let’s go through an example 1000 – 254 (1000 is base for all three-digit numbers):

1. Subtract each digit from 9 (except the one’s place):
   • 9 – 2 = 7
   • 9 – 5 = 4
2. Subtract the last digit (4) from 10: 10 – 4 = 6

So, 254 subtracted from 1000 (or 10 times 100) using the “all from nine, last from ten” trick equals 746.

Practicing Mental Math for Efficiency and Accuracy

Consistent practice is key to mastering mental math. Incorporate mental math exercises into your daily routine, such as solving math problems mentally, playing math games, and participating in mental math competitions. Focus on speed without compromising accuracy, and gradually increase the complexity of calculations as your skills improve.

Challenge: Try It Out!

Here’s a fun challenge for you: Calculate the following mentally and comment your answer below!

Challenge: 72 × 5 + 130 ÷ 5 – 20

Interactive Engagement: Let’s Connect!

Are you ready to unleash the power of mental math? As an expert Vedic mathematics tutor, I’m here to guide you through mastering mental math techniques for lightning-fast calculations.

Share this blog with your friends and family to spread the joy of mental math! Join our community of students and parents for interactive learning and support.

Stay tuned for our next blog, where we’ll explore the world of numerical estimation and how it can enhance your problem-solving skills. Keep practicing, keep calculating, and let’s make math exciting together!

Don’t forget to comment your answer for the given challenge!