SELINAP.COM

Multiplication of 2 numbers that are near to 100 or 1000

Friday, January 16th, 2009

Subscribe.
Enter your email:

This tip is suitable for multiplying two numbers that are near to 100. For example, 103 x 104 and 97 x 98.

Example 1:

To calculate 103 x 104:

1. Add the the ones from the multiplicand to the multiplier.
   103 + 4 = 107.
2. Multiply the ones from the multiplier with the ones from the multiplicand.
   3 x 4 = 12.
3. Concatenate the results from step 1 and 2. Therefore, 103 x 104 = 10712.

Example 2:

To calculate 1005 x 1002:

1. Add the the ones from the multiplicand to the multiplier.
   1005 + 2 = 1007.
2. Multiply the ones from the multiplier with the ones from the multiplicand. Prepend a zero to the result.
   5 x 1 = 010.
3. Concatenate the results from step 1 and 2. Therefore, 1005 x 1002 = 1007010.

Example 3:

To calculate 97 x 98:

1. Subtract from 10, the ones from multiplicand.
   10 – 8 = 2.
2. Subtract from multiplier, the result from step 1.
   97 – 2 = 95.
3. Subtract from 10, the ones from multiplier.
   10 – 7 = 3.
4. Multiply the result from step 3 with the result from 1. Prepend a zero.
   2 x 3 = 06.
5. Concatenate the results from step 2 and step 4. Therefore, 97 x 98 = 9506.

Example 4:

To calculate 993 x 995:

1. Subtract from 10, the ones from multiplicand.
   10 – 5 = 5.
2. Subtract from multiplier, the result from step 1.
   993 – 5 = 988.
3. Subtract from 10, the ones from multiplier.
   10 – 3 = 7.
4. Multiply the result from step 3 with the result from 1. If you get a one digit number, prepend two zeroes, otherwise prepend just one zero.
   5 x 7 = 035.
5. Concatenate the results from step 2 and step 4. Therefore, 993 x 995 = 988035.

Exercise:

If domain name is cost $9.90 each, what is the cost if you want to buy 92 domain?

If you are new here, you might want to subscribe to the RSS feed or newsletter.

Enter your email address:

Creates the exact copy of your hard disk and allows you to instantly restore the entire machine.
New Acronis True Image Home 2010 is the most reliable and easy in use backup solution. Now with online backup option!
15% Discount Code: FMAATIH2010

What else?

• Multiplication of any number by a number near 100
• Multiply a number by 11
• Product of a single digit number with 9
• Box multiplication
• Multiply two 3 digits numbers in your head

Like this article? Share it

           

5 Responses to “Multiplication of 2 numbers that are near to 100 or 1000”

1. KH says:

   January 16, 2009 at 9:49 pm

   Great technique! Very useful today where most of the prices around end with 9-something(eg 9.99, 9.97).

   KHs last blog post..Words from The Old Man

   Reply
2. KNizam says:

   January 18, 2009 at 8:48 pm

   perghhhhhhhhhhh neh betul2 minimalist neh.
   hehe i like !

   Reply
   • Selinap says:

     January 19, 2009 at 12:00 am

     Thank you.

     Reply
3. kkraghuthaman says:

   July 20, 2009 at 12:48 am

   A Vedic matrix 0…9 is given below!

   ..0…..1…..2…..3…..4…..5…..6…..7…..8…..9
   —– —– —– —– —– —– —– —– —– —–
   0
   —– —– —– —– —– —– —– —– —– —–
   1
   —– —– —– —– —– —– —– —– —– —–
   2
   —– —– —– —– —– —– —– —– —– —–
   3
   —– —– —– —– —– —– —– —– —– —–
   4
   —– —– —– —– —– —– —– —– —– —–
   5
   —– —– —– —– —– —– —– —– —– —–
   6
   —– —– —– —– —– —– —– —– —– —–
   7
   —– —– —– —– —– —– —– —– —– —–
   8
   —– —– —– —– —– —– —– —– —– —–
   9…………………………………….97

   97 is ‘3 less than’ a 100. It means (+97-3) position
   89 is ‘11 less tham’ a 100. It means(+89-11) position’

   See that 97-11= 86 and 89-3= 86
   Merge (-3)*(-11)= 33 to right of 86 as 8633.
   97*89= 8633

   Reply
4. kkraghuthaman says:

   July 20, 2009 at 12:58 am

   .0….1….2….3….4….5….6….7….8….9
   —– —– —– —– —– —– —– —– —– —–
   0
   —– —– —– —– —– —– —– —– —– —–
   1
   —– —– —– —– —– —– —– —– —– —–
   2
   —– —– —– —– —– —– —– —– —– —–
   3
   —– —– —– —– —– —– —– —– —– —–
   4
   —– —– —– —– —– —– —– —– —– —–
   5
   —– —– —– —– —– —– —– —– —– —–
   6
   —– —– —– —– —– —– —– —– —– —–
   7
   —– —– —– —– —– —– —– —– —– —–
   8
   —– —– —– —– —– —– —– 97 —– —–
   9

   97 is a position that has 97 ones before it.
   So (+97-3)is written!
   89 is (+89-11)!
   Basics shall be correct!

   Reply