Wednesday, September 21, 2016

Few videos on Mathematics

Found few videos on facebook by Mr.K.Seenuvasan, a B.T Assistant in Mathematics, working in Government Middle School , Villupuram.

Hope these videos are helpful.

A video song on Fractions.

video

A video on writing Number names using Indian Numerical System and Multinational Numerical System

video

This is the teacher's facebook page https://www.facebook.com/kseenu.vasan?fref=ts.

Tuesday, June 24, 2014

Method to calculate the Square of the numbers with the unit digit 1

 Inorder to calculate the square of the numbers with their unit digit " 1", just add the square of the previous number, the previous number and the number given.

For example, 

11 ^ 2 = 10 ^ 2  + 10 + 11 = 100 + 10 + 11 = 121
91 ^ 2 = 90 ^ 2  + 90 + 91 = 8100 + 90 + 91 = 8281


Thanks, Numbersmania -Where MATHS is Life Facebook Page.

Wednesday, April 2, 2014

Mystery Number



Find the number $x$ that satisfies these two properties:
  • The digits of $x$ add up to a number $y$ where $x$ equals $y$ times the number you get when you reverse the digits of $y$.
  • Reverse the digits of $x$ and find the prime factors of the number you get. Then take the sum of the squares of these prime factors and halve it. Removing the digit 0 from the new number yields back $x$
Hint : $x$ is a four digit number.

http://plus.maths.org/content/mystery-number


Solution

The answer is 1729.  The number is known as the Hardy-Ramanujan number after Ramanujan and the mathematician and Godfrey Hardy. It has another interesting property: you can write it as a sum of cubes in two different ways:
\[  1729 = 1^3+12^3=9^3+10^3. \]
Ramanujan Srinivasa Ramanujan, 1887-1920.

Hardy told the following story: "I remember once going to see [Ramanujan] when he was ill at Putney. I had ridden in taxi cab number 1729 and remarked that the number seemed to me rather a dull one, and that I hoped it was not an unfavorable omen. 'No,' he replied, 'it is a very interesting number; it is the smallest number expressible as the sum of two cubes in two different ways.' "


http://plus.maths.org/content/mystery-number 

Tuesday, March 4, 2014

Mathematical Anagrams

An anagram is a word or phrase made up of the letters of another word.
These are all made up from maths words.


Friends, Kindly post the answers in the comment.

Source: Mathsphere math puzzles
 

Thursday, February 20, 2014

An Intelligence test

 Photo: This is a little intelligence test. Share if you understood it. :) www.voca-people.com
 How is this possible ?


The sum of the numbers form the last  two digits and the difference between the numbers form the first digit.

Saturday, January 11, 2014

Peculiar Numbers





The 3 digit numbers 407 and 370 have this peculiarity, that they exactly equal the sum of the cubes of their digits. Thus the cube of 4 is 64, the cube of 0 is 0, and the cube of7 is 343. Add together 64, 0, and 343, and you get 407. Again, the cube of 3 (27), added to the cube of 7 (343), is 370. Can you find a number not containing a zero that will work in the same way? 


Solution: 

The other Numbers are 153 , 371.

   153 = 1 ^ 3 + 5 ^ 3 + 3 ^ 3 = 1 + 125 + 27 =  153

   371 = 3 ^ 3 + 7 ^ 3 + 1 ^ 3 = 27 + 343 + 1 = 371


Other numbers whose cube value are also same as the original number are 0 and 1.

    0   = 0 ^ 3 = 0

    1   = 1 ^ 3 = 1

   

Friends, If you could find any other such numbers...kindly let me know.


Thanks,