Results 1 to 8 of 8

Thread: Squaring a two or three digit number ending in 5.

  1. #1






    darani is offline
    Senior Member Array
    Join Date
    Nov 2006
    Age
    31
    Posts
    5,995
    Country: India
    Rep Power
    0


    Squaring a two or three digit number ending in 5.

    If you need to square a number (two or three digits) that ends in 5, just use this trick. First, you should know that when any number squared that ends in 5 will always have the last two digits of 25. Then all ya need to do is look at the digits before the 5 and multiply it (them) by the next number higher and put that infront of the 25.

    Here's two examples:

    1) 35 squared is 3 times 4 (one higher than 3) or 12 and put that in front of 25. Looks like this... 1225

    2) 65 squared is 6 times 7 (one higher than 6) or 42 and put that in front of 25. Looks like this .... 4225












  2. #2
    Senior Member Array
    Join Date
    Nov 2006
    Age
    31
    Posts
    5,995
    Country: India
    Rep Power
    0

    Play in the minds of ur frnds..

    "I can add very fast," boasted Billy. "Here, I'll show you. In this calendar, I want you to choose some full week of 7 days. It can be any wekk in any month as long as it has 7 days. Now add the numbers in that week. But don't tell me the sum. Just tell me the number of the first day of the week, and I'll find the sum, too."


    Mary chose the week of April 8. Shee added the numbers very carefully. (Did she get 77?)


    "I'm ready," said Mary. "I chose the week in April beginning on the eighth."


    "Then your sum is 77," said Billy after a breif moment.


    "That's right, Billy. How did you add it so fast?"




    The key is : If u want the key i need some replies for this to kow it.
    ha ha ha



  3. #3
    Senior Member Array
    Join Date
    Nov 2006
    Age
    31
    Posts
    5,995
    Country: India
    Rep Power
    0

    Number 8 magic...

    An interesting number is 8. Make a complete table of 8's as started below.

    1 x 8 = 8 (0+8 =


    2 x 8 = 16 (1+6 = 7)



    3 x 8 = 24 (2+4 = 6)



    4 x 8 = 32 (3+2 = 5)

    5 x 8 = 40 (4+0 = 4)

    6 x 8 = 48 (4+8 = 12 ; 1+2 =3)

    7 x 8 = 56 (5+6 = 11 ; 1+1 = 2)

    8 x 8 = 64 (6+4 = 10 ; 1+0 = 1)



    Similarly we can do for 8 x (19,20,....,26)



  4. #4
    Senior Member Array
    Join Date
    Nov 2006
    Age
    31
    Posts
    5,995
    Country: India
    Rep Power
    0

    Magic with number 6

    6 x 2 = 12 (1 + 2 = 3)
    6 x 3 = 18 (1 + 8 = 9)
    6 x 4 = 24 (2 + 4 = 6)

    6 x 5 = 30 (3 + 0 = 3)
    6 x 6 = 36 (3 + 6 = 9)
    6 x 7 = 42 (4 + 2 = 6)

    6 x 8 = 48 (4 + 8 = 12) (1 + 2 = 3)
    6 x 9 = 54 (5 + 4 = 9)
    6 x 10 = 60 (6 + 0 = 6)



    It goes on and on.. try with any number.



  5. #5
    Senior Member Array
    Join Date
    Nov 2006
    Age
    31
    Posts
    5,995
    Country: India
    Rep Power
    0

    Make ur frnd breathless with finding the the time he thinks.

    Ask your friend to think of any hour on the clock without telling you. Explain that you are going to point randomly to different numbers on the clock while he silently counts up to 20. Tell him to start with the hour that he is thinking of and add one every time you point to a number.



    Example: He's thinking of 8:00 so he counts

    9 when you point to the first number,

    10 when you point to the second number,

    etc.

    When he gets to 20, he should say, "Stop!", and your pencil will be pointing to the hour that he is thinking of!

    How to Do It

    As your friend is counting up to 20, you are counting, too. The first seven numbers that you point to can be any numbers on the clock. However, the eighth number must be 12. Then go backwards around the clock until your friend tells you to stop.



  6. #6
    Senior Member Array
    Join Date
    Nov 2006
    Age
    31
    Posts
    5,995
    Country: India
    Rep Power
    0

    Fun with numbers 1 to 9...

    Start with the sequence of non-zero digits 123456789. The problem is to place plus or minus signs between them so that the result of thus described arithmetic operation will be 100.






    12+3-4+5+67+8+9=100

    123+4-5+67-89=100

    1+2+34-5+67-8+9=100

    12+3-4+5+67+8+9=100

    123-4-5-6-7+8-9=100

    123+4-5+67-89=100

    123+45-67+8-9=100

    123-45-67+89=100

    12-3-4+5-6+7+89=100

    12+3+4+5-6-7+89=100

    1+23-4+5+6+78-9=100

    1+23-4+56+7+8+9=100

    1+2+3-4+5+6+78+9=100





    If we put a "-" before 1, we have one more solution:

    -1+2-3+4+5+6+78+9=100

    Using the "." decimal separation I found another solution:

    1+2.3-4+5+6.7+89=100 (solution of my own)








    Now we c for the 9 8 7 6 5 4 3 2 1

    98-76+54+3+21=100

    9-8+76+54-32+1=100

    98+7+6-5-4-3+2-1=100

    98-7-6-5-4+3+21=100

    9-8+76-5+4+3+21=100

    98-7+6+5+4-3-2-1=100

    98+7-6+5-4+3-2-1=100

    98+7-6+5-4-3+2+1=100

    98-7+6+5-4+3-2+1=100

    98-7+6-5+4+3+2-1=100

    98+7-6-5+4+3-2-1=100

    98-7-6+5+4+3+2+1=100

    9+8+76+5+4-3+2-1=100

    9+8+76+5-4+3+2+1=100

    9-8+7+65-4+32-1=100

    Write the sign "-", three solutions:

    -9+8+76+5-4+3+21=100

    -9+8+7+65-4+32+1=100

    -9-8+76-5+43+2+1=100

    With the decimal point:

    9+87.6+5.4-3+2-1=100 (solution of my own)

    If I "shuffle" the digits there are many solutions. I found some when I was young, for example:

    91+7.68+5.32-4=100

    98.3+6.4-5.7+2-1=100

    538+7-429-13=100

    (8x9.125)+37-6-4=100 etc etc etc ..



  7. #7
    Member Array
    Join Date
    Jul 2008
    Age
    31
    Posts
    3,643
    Country: United States
    Rep Power
    0
    Cool Info. Duke can you shift this topic to educational materials or can any MOD can do this???



  8. #8
    Senior Member Array sunnyajmal's Avatar
    Join Date
    Feb 2008
    Location
    Hearts
    Posts
    28,984
    Country: Afghanistan
    Rep Power
    0
    coolz...



Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)







Similar Threads

  1. Never ending 5 min.
    By Tahir Bati in forum Jokes
    Replies: 0
    Last Post: 03-25-2015, 07:33 PM
  2. Every story has an ending
    By Aamia in forum Inspirations
    Replies: 0
    Last Post: 03-12-2014, 03:00 PM
  3. Never Ending Commitment
    By Tahir Bati in forum Inspirations
    Replies: 0
    Last Post: 05-03-2013, 07:57 PM
  4. Ending
    By Tahir Bati in forum Inspirations
    Replies: 0
    Last Post: 04-11-2013, 08:22 PM
  5. Ending
    By Tahir Bati in forum Inspirations
    Replies: 0
    Last Post: 01-11-2013, 08:43 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  








Like us on Facebook | Get Website Updates | Get our E-Magazine


Get Daily Forum Updates

Get Most Amazing E-mails Daily
Full of amazing emails daily in your inbox
»» Join Nidokidos E-mail Magazine
Join Nidokidos Official Page on Facebook