Nice device to put CSR money

This idea i am going to give is neither revolutionary nor profound, not even going to make money. But it will help persons with vision disability. Though, these kind of devices are available, we will throw light to its existence, so that it is widely available at a low cost, instead of spending money in braille books. If a person who is visually impaired wants to read a document or book or any kind of letter, he can use this hand scanner and text to speech converter to read aloud (or use ear phones) any book, any letter or any kind of printed documents. The device may also be designed particularly to read books. Turn pages automatically and read. The user will have buttons to Play/ Pause/ Rewind/ GoToPage/ GoToChapter. They can use voice commands also. The technology required to make this device is very much available. We just need some will from Governments and Corporates to make these devices( may be as part of CSR activity) and provide it free of cost to visually impaired persons.

Algorithm behind Division - Kid's Time

Long Division

What is Division? It is the process of splitting a number ( dividend ) into chunks of another number ( divisor ) and calculating how many pieces (quotient ) have been obtained as the result of division.

Example 6/2 = 3

Now , we will discuss about the long division. We will divide 1334/2 and the result is 667.

The idea behind long division is to find the most significant digit of the quotient which will fit in its place in every iteration. In this example, we first check first digit of dividend( 1 in this case). It is less than 2 and with that we will not be able to find the most significant digit of the quotient. So we move on to next digit. Now, we take 13. We divide 13 by 2. Now the most significant digit will not exceed 6 and will not be less than 6. Why? Because no matter what digits or how many digits follow 13, when we divide it by 2, it has to 6xxx for any 13xxx ( or 6xx for 13xx, for any number of x, the same result holds). In the next step, we are passing the remainder of 13/2 to next significant digit.

For Example. if we divide 92/4, the most significant digit will be 2 (got by calculating 9/4 and next significant digit will be 10 + 2 ( 10 carried from remainder of first digit calculation)  = 12/4  = 3. First digit 2, second digit 3 Answer is 23. The idea is like multiplication, where we pass on 1 of 12(result of least significant digit multiplication) as 1 to next digit multiplication. In Division, we pass 1 (remainder of most significant digit division) as 10+2 to next digit division.

So, coming back to previous example, when we divide 13/2, it gives the next digit 6, then 1 goes to next significant digit as 10+4. When we divide 14/2, We get the next digit 7. The result is 667.

We can understand this through another example -  1445/5


First, We take the number 14 ( the left most digits of dividend which is greater than 5). We divide it with 5 to get the left most digit ( Most significant digit ) of quotient and pass on the remainder to next digit. When passing we multiply the remainder with 10, because when shifting right to the adjacent digit, the value increases 10 times no matter the place of the digit. Then we add the remainder multiplied by 10 of the previous digit with next digit right of it ( Next significant digit). We get 40 + 4. Then again we divide 44 with 5 and so on. The process continues and in every step we get one digit of quotient ( In the order from left most to right most digit). We need not worry whether the first digit of the quotient( Left most ) is in 1000th place or 100th place or whatever, because at last the quotient is going to be filled with exact number of digits ( produced at every step ), which divides the dividend.



For better understanding, Consider this

Algorithm behind Multiplication - Kids Time

Multiplication

What is multiplication? It is the process of adding a number to itself as many times as given by the multiplier.

Example   2*3. Add 2 with itself 3 times.  2+2+2 = 6

 Or            3*2. Add 3 with itself 2 times.      3+3 = 6

Example   3*5. Add 3 with itself 5 times. 3+3+3+3+3 = 15

Or             5*3. Add 5 with itself 3 times          5+5+5 = 15

With that basics, We will move on to two digit multiplication.

Example  23 * 24 = 552. Add 23 with itself 24 times. 

That's bit lengthy. So we will break it into pieces.

Add 23 with itself 20 times + Add 23 with itself 4 times.

23 * 20 + 23 * 4.

We know that 

To add 23 with itself 20 times = (Add 23 with itself 2 times) * 10 = ( 23 + 23 ) * 10 = 460

Now

Add 23 with itself 4 times. 23 + 23 + 23 + 23 = 92

The result is 460 + 92 = 552.

Now we will learn about the process of multiplication.

Another Example