Fun with Number 14

                                                        14 Pounds = 1 Stone

                                                        14 Days = Fortnight

                                                        14 = 2 x 7 (Product of two prime numbers)

Interesting Facts For Number 13

                                      (13)² = 169  and   (31)² =961

                                     13 is the  6^th  prime number. 

                                                  13 is the 7^th   Fibonacci number. 

                                                              There are 13 cards in a suit.

                                                                           13 = (3)² +  (2)²             

 

 

Number Wheel ....Teaches Times Table of 4 & 6

Number Wheel .. Unique way of learning times table of 2 &8

Watch this video..

Times Table of 7 using Tic Tac Toe Square

Learn Times table of 7 in two simple steps.

STEP I

Draw Tic Tac Toe Square and numbered them as shown below :-

STEP II

Insert 0 ,1 , 2  in first row.

Insert 2 ,3 ,4 in second row.

Insert 4, 5, 6 in third row.

As shown below:-

Practice it several times by drawing and revising it again and again.

Interesting way to learn multiplication table of 9... ur kid will enjoy..

Making your kid learn times tables is a herculean task  for all mothers,Watch this video and let your child enjoy the learning .

Watch the video below to learn multiplication table of 9.

Table of 3 using Tic Tac Toe square

Learn Times Table of 3 in two simple steps.

STEP I

Draw Tic Tac Toe Square and numbered them as shown below:-

STEP II

Insert 0 in first row.

Insert 1 in second row.

Insert 2 in third row.

As shown below:-

Times Table of 3 is ready. Make your kid practise this square by drawing again and again . Let them say it loudly.. Without effort 3 times table can be learnt.

Correct Division sums yourself..

We all are aware of the very famous division check formula . It says

Dividend = Divisor * Quotient + Remainder

Again solving this formula with actual value is time consuming so just put the digital root of all the values and see the fun yourself.  let me explain with the help of an example..

1. Divide  254(Dividend) by 12(Divisor).

2. Quotient is 21 and remainder is 2.

3. Digital root of Dividend 254 is 2.

4. Digital root of Divisor  12 is 3.

5. Digital root of quotient 21 is 3.

6. Digital root of   Remainder 2 is 2.

7. Now put all the digital root values in the formula as shown here:-

                              Dividend = Divisor * Quotient + Remainder

                                 2          =  3        *     3        +     2

                                 2         =   9 + 2

                                 2         =    11( Digital root of  11 is 2)

                   Hence     2       =     2

Hence the digital root of left hand side is equal to the right hand side.


Practise them and enjoy maths...

Check Multiplication Sums Using Digital Root

In Previous post we learn about how to check addition and  subtraction using digital root.
Now a smarter way of checking multiplication sums.

REMEMBER

The digital root of a product is the product  of the digital roots

of the numbers being multiplied.

Lets understand by an example.

1. Multiply  two numbers 254 * 231

2. Digital root of 254 is2

3. Digital root of 231 is 6

4. Now Multiply 2*6 is 12. Further digital root of 12 is 3.

This implies that Digital root of  254 * 231  will also be 3. Let's verify.

5. Multiply 254 * 231 = 58674

6. Digital root of   58674  is 5+8+6+7+4= 30 again 3+0 = 3

Hence the digital root of the final answer is equal to the product  of the digital roots of 2 numbers.


Practise to master this art.   Enjoy maths..

Check subtraction using Digital Roots

In my previous post, we learnt about checking addition sums using digital root.

Now we will learn checking subtraction sums using digital root.

REMEMBER

The digital root of a difference is the difference of the digital roots

of the numbers in the subtraction.

We will understand this concept by taking two cases:-

Case I--- When digital root of greater number is greater then the digital root of lesser no. In this case we get positive digital root.

Case II--- When the digital root of greater no. is lesser than the digital root of lesser number. In this case we get negative digital root.

Case I

1. Subtract two numbers 872 - 411.

2. Digital root of 872 is 8

3. Digital root of 411 is 6

4. Now subtract 8-6 is 2.

This implies that Digital root of 872 - 411 will also be 2. Let's verify.

5. Subtract 872 - 411 = 461

6. Digital root of 461 is4+6+1=11 again 1+1 = 2.

Hence the digital root of the final answer is equal to the difference of the digital roots of 2 numbers.

Case II

1. Subtract two numbers 663 - 567.

2. Digital root of 663 is 6

3. Digital root of 567 is 9

4. Now subtract 6-9 is -3.

5. Here we observe that we get a negative digital root.

5. Subtract 663 - 567 = 96

6. Digital root of 96 is 6.

7. Here we observe that there is a mismatch in the digital roots ie. -3 & 6.

8. Always remember in subtraction we may get negative digital root so to make it positive we will take the complement of digital root with 9 ie. 9-3 =6. Now both the digital roots are same and we get the answer right.

Check addition sums in seconds

Today we will learn a property of digital root to check addition sums.

REMEMBER

The digital root of a sum is the sum of the digital roots of the numbers being added.

Above statement may look confusing, but it will be easy in a short while. Lets understand this by a example.

1. Add two numbers 354 + 212.

2. Digital root of 354 is 3

3. Digital root of 212 is 5

4. Now add 3+5 is 8.

This implies that Digital root of 354+212 will also be 8. Let's verify.

5. Addition of 354+212=566

6. Digital root of 566 is 5+6+6=17 again 1+7 = 8

Hence the digital root of the final answer is equal to the sum of the digital roots of 2 numbers.

Using this property multiple choice questions can be solved in seconds. For example.

Example 1. 2827+3285+5025 = ?

(a) 10137 (b) 11137 (c) 10187 (d) 11257

Now to solve this problem find digital root of nos:

DR of 2827 is 1

DR of 3285 is 9

DR of 5025 is 3

Add 9+1+3=13 again 1+3=4

Now find the digital root of all the answer, the digital root of which ever option matches with 4 will be the answer. Let's see.

(a) 10137-- Digital root is 3

(b) 11137---Digital root is 4

(c) 10187---- Digital root is 8

(d) 11257--- Digital root is 7

So the answer is option (b).

This way, by adding digital roots we can get the correct answer in competitive exams and it saves lot of time.

DIGITAL ROOTS

Digital root is a concept we all know but hardly use. All of us have used digital roots to check the divisibility of 3 and 9 but its application are lot more than this. It can be used to check the correctness of addition, subtraction, multiplication, division and lots more.

CONCEPT 1

What is digital roots ?

Digital root is sum of all the digits of a number, continued until there is only one digit left.

Eg. 1. Digtal root of 123 is 1+2+3=6

Eg. 2. Digital root of 563281 is 5+6+3+2+8+1=25 again 2+5=7,

so digital root of 563281 is 7.

I hope its clear,please post your doubts.

CONCEPT 2

CASTING OUT NINE METHOD

(Elimination and Retention)

Lets try to find out the digital root of 2637896.So 2+6+3+7+8+9+6 = 41 then again 4+1=5 so digital root is 5.

So we have observed that finding the digital root of large numbers is actually a cumbersome process. That's why this method gives a faster way for calculating digital roots.

In casting out nine method, we eliminate 9 or group of digit add upto 9. Then the numbers which are left at the end are added up for the digital root. Lets understand this by some examples:-

Eg 1. Digital Root of 93 is 3 ( as we have cast out nine and the number 3 is the digital root.)

Eg.2 Digital root of 732 is 3 ( as we have cast out 7+2makes 9 hence 3 is the digital root.)

Eg.3 Digital root of 9743821 is 7 ( as we cast out 9, 7&2 and 8&1 so 4 &3 are added to get 7 so 7 is the digital root.)

Just try to gain expertise, by practise.