## Mentally Multiply by 5, 25, 50, 250

This is a simple quicker math trick but it can be very useful for young students to solve seemingly difficult calculations. I will be glad to get your feedback on this.

### Mental multiplication by 5, 25, 50, 250, 500 and so on.

Any number can be expressed in different ways. For example, 5 can be expressed as 10x(1/2).

Trick: Multiplication by 5

Step 1: Multiply the number by 10, i.e. simply place a zero after the number.

Step 2: Halve the resultant number.

Example 1:

5 × 136 = ten times of 136 i.e. 1360 should be divided by 2 = 1360/2 = 680

Example 2:

5 × 343, half of 3430 is 1715

Also check out, how to mentally multiply by 111? Read More

## Vedic Multiplication Trick for 2 Numbers Starting with Same Digits

Multiplication Method – multiplying 2 numbers starting with same digit(s)

This vedic maths trick will help you in multiplying two numbers when these numbers start with the same digit. For example 34 x 37; see their ten’s digit (starting digit) is same. Another example can be 234 x 232, see their hundred’s and ten’s digits (starting two digits) are same.

In one of the earlier post a similar method was described. In that like this trick the starting digit(s) should be same but at the same time the sum of digit at unit’s place should be 10 – please check that out – Vedic multiplication

Learn Multiplication

34 x 37

To multiply 34×37, we know they are in the base 30. Hence the reference point (base) will be 30.

Step 1.

Determine how much more is 34 from 30. The answer is 4

Determine how much more is 37 from 30. The answer is 7

Step 2.

Either add 4 to 37 = 41 or 7 to 34 = 41.

The result will be same always.

Step 3.

Multiply the resultant number from step 2 by the base, which is in this case 30

41×30 = 41x3x10 = 123×10 = 1230

Step 4.

Add to the resultant of step 3 the product of the numbers obtained from step 1. This will give you the answer.

1230+ (4×7) = 1230 + 28 = 1258

Another example,

23 x 29

From step 1 and step 2 above, 23 + 9 = 32 or 29 + 3 = 32

From step 3 : 32 x 20 = 640

From step 4 : 640 + (3×9) = 667

One more example,

234 x 232

From step 1 and step 2 above, 234 +2 = 236 or 232 + 4 = 236

From step 3 : 236 x 230 = 54280

From step 4 : 54280 + (4×2) = 54288

using the above method can also be used for multiplying two numbers close to humdred

## Vedic Division by Nine

Friends, this time it has been a long time I have written a post. I badly wanted to write one but because of very busy schedule I couldn’t.

This post is one of the many areas where Vedic Mathematics really surpasses traditional methods as you shall soon see. This post is about dividing any number by 9.

We will start by taking an example

Divide 200103002 by 9

## Division in Vedic Mathematics

There are so many shortcuts for multiplication but hardly any shortcuts for division. Nandeesh has translated a Sanskrit Sutra to reduce long division to one line short-cut. Join me in thanking him for his great efforts.

Long Division reduced to one-line shortcut

Example 1:  716769 ÷ 54.

Reduce the divisor 54 to 5 pushing the remaining digit 4 “on top of the flag” (Dhvajanka so to say).

Corresponding to the number of digits flagged on top (in this case, one), the rightmost part of the number to be divided is split to mark the placeholder of the decimal point or the remainder portion.

Let us walk through the steps of this example:
716769 ÷ 54 = 13273.5 Read More

## Quick Multiplication up to 20 x 20

“I’m having trouble above 10×10.”

This was a statement I heard many times while interacting with students preparing for competitive examinations including CAT. This was in response to my appeal to them to memorize tables up to 20×20.

Today I am posting here on QuickerMaths.com, the method which I recommend to my students too.

How to multiply up to 20×20 in your head?

Assumption: You know your multiplication table reasonably well up to 10×10.

I am trying to explain this with an example, Read More

## Shortcut Method for Multiplication

A guest post by Nandeesh H.N. of Kolkata

Shortcut multiplication for approximate numbers

When applying the rules of multiplication of exact numbers to approximate numbers we waste time and effort in the computation of digits that will be dropped at a later stage. The computation can be made more efficient if we are guided by the following rules:

## Simple Fast Multiplication Tricks & Techniques

Fast Multiplication by 5: Multiply by 10 (just place 0 after the original number) and divide the result by 2.
Fast Multiplication by 6: Sometimes subsequent multiplication by 3 and then 2 is easy.
Fast Multiplication by 9: Multiply by 10 (just place 0 after the original number) and subtract the original number.
Multiply by 12: Multiply by 10 and add twice the original number.
Multiply by 13: Multiply by 3 and add 10 times original number.
Multiply by 14: Multiply by 7 and then multiply by 2
Multiply by 15: Multiply by 10 and add 5 times the original number, as above.
Multiply by 16: You can double four times, if you want to. Or you can multiply by 8 and then by 2.
Multiply by 17: Multiply by 7 and add 10 times original number.
Multiply by 18: Multiply by 20 and subtract twice the original number (which is obvious from the first step).
Multiply by 19: Multiply by 20 and subtract the original number.
Multiply by 24: Multiply by 8 and then multiply by 3.
Multiply by 27: Multiply by 30 and subtract 3 times the original number (which is obvious from the first step).
Multiply by 45: Multiply by 50 and subtract 5 times the original number (which is obvious from the first step).
Multiply by 90: Multiply by 9 (as above) and put a zero on the right.
Multiply by 98: Multiply by 100 (just place 00 after the original number)and subtract twice the original number.
Multiply by 99: Multiply by 100 (just place 00 after the original number)and subtract the original number.

Did you liked the above fast multiplication tricks ?

## Fast Multiplication by 5

This fast calculation trick or vedic maths trick will teach you how to multiply any number by 5. The concept can be divided in two parts as shown-
MULTIPLYING 5 TIMES AN EVEN NUMBER
Memory Trick: Halve the number you are multiplying by and place a zero after the number.
Example:
i. 5 × 136, half of 136 is 68, add a zero for an answer of 680.
ii. 5 × 874, half of 874 is 437; add a zero for an answer of 4370.
MULTIPLYING 5 TIMES AN ODD NUMBER: subtract one from the number you are multiplying, then halve that number and place a 5 after the resulting number.
Example:
343 x 5 = (343-1)/2 | 5 =  1715

This fast calculation trick or vedic maths trick will teach you how to multiply any number by 5. The concept can be divided in two parts as shown-

MULTIPLYING 5 TIMES AN EVEN NUMBER

Memory Trick: Halve the number you are multiplying by and place a zero after the number.

Example:

i. 5 × 136, half of 136 is 68, add a zero for an answer of 680.

ii. 5 × 874, half of 874 is 437; add a zero for an answer of 4370.

MULTIPLYING 5 TIMES AN ODD NUMBER: subtract one from the number Read More

## Vedic Multiplication of two numbers close to Hundred

Vedic Method of Multiplication: Base System of multiplication

Application: Multiplication of two numbers close to Hundred

Case 1: Both numbers greater than 100.

Rule: You will get the answer in two parts

First part, to get left hand side of the answer: Add the difference between 100 and either of the numbers to the other number

Second part, to get right hand side of the answer: multiply the difference from 100 of both the numbers

Example

103 x 104 = 10712

The answer is in two parts: 107 and 12,

107 is just 103 + 4 (or 104 + 3), and 12 is just 3 x 4.

Similarly 107 x 106 = 11342

107 + 6 = 113 and 7 x 6 = 42

123 x 103 = 12669

(123 + 3) | (23 x 3) = 126 | 69 =12669 .

If the multiplication of the offsets is more than 100 then this method won’t work. For example 123 x 105. Here offsets are 23 and 5.

Multiplication of 23 and 5 is 115 which are more than 100. So this method won’t work.

But it can still work with a little modification. Consider the following examples:

Example 1

122 x 123 = 15006

Step 1: 22 x 23 = 506 (as done earlier)

Step 2: 122 + 23 (as done earlier)

Step 3: Add the 5 (digit at 100s place) of 506 to step 2

Answer: (122 + 23 + 5) | (22 x 23) = 150 | 06 = 10506

Example 2

123 x 105 (Different representation but same method)

123 + 5 = 128

23 x 5 = 115

128 | 115

= 12915

In the next post I’ll tell you about vedic multiplication, i.e.,  how to multiply two numbers lesser than the base (in this case 100).

Here’s the promised post for you – http://www.quickermaths.com/base-method-of-multiplication/

If you liked this method of vedic multiplication included in ancient Vedic Maths, Please leave a comment to let us know.

## Vedic Multiplication by 9, 99, 999 and so on

When any number has to be multiplied by a series of 9s, like 9, 99, 999, 9999 and so on than we can apply this very simple vedic maths technique to increase your speed of calculation.

Multiplication with 9/ 99 / 999 and so on.

we know, 789 × 999 = 788,211

You will get the answers in two parts,

• The left hand side of the answer: subtract 1 from 789, which is 788
• The right hand side of the answer subtract 789 from 1000 = 1000-789= 211

Thus, 999 x 789 = 789-1   |  1000-789 = 788, 211 (answer)

{for the right hand side of the answer, 789 should be subtracted from (999+1)}

or,  99999 x 78 = 78-1   | 100000 – 78

= 7799922

{78 should be subtracted from (99999+1)}

Another example:

1203579 × 9999999 = 1203579-1   | 10000000- 1203579

=120357887964 21

Number in red is 1 less than 1203579. Number in blue is (10000000-1203579). Hence the answer.

This method has to be altered a little bit when number of 9s are lessers than the number of digit in the divisor.

1432  x 9 = 1432 (10 – 1) = 14320 – 1432 = 12888

So for multiplication with 9, put a zero after that number and subtract the number itself from that.

Likewise for 99 put two zeroes after that number .

3256 x 99 = 325600 – 3256 =  322344