Easy Multiplication of 5 digit numbers

Multiplication of two five digit numbers

Suppose we have to multiply two 5 digit numbers like

   3 5 4 1 2

x 2 6 3 4 1

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Easy Calculation

Division of any big number ending in five by any two digit number ending in five can be done with just mind calculation if you use the following technique:

Suppose let us take the example 1625 divided by 35

Fun Maths

If you multiply any three digit number by 11 and then again multiply the product with 91 then see the result.

For example

Let us take a 3 digit number 578

now 578 x 11 = 6358

then 6358 x 91 = 578578

see the number 578  repeats in the result

Multiplying Consecutive Numbers

Suppose we have to multiply two consecutive numbers say n and n+1

then n x (n+1) = n² + n

If we take it in the reverse way, say (n-1) and n

then (n-1) x n = n² – n

We can apply this for speed calculation,

Fun Numbers Part 3

One in numbers make it fun for its operations. Multiply one with any number the result will be the number itself same for the operation division also.. Let us check some operations with 1.

Squaring 3 digit numbers ending in 1

There is a short cut method for squaring 3 digit numbers ending in 1 rather than going for normal multiplication. If you can practice a bit with this method then you can square such numbers in mind itself. Let me explain the method with an example.

Squaring of 3 digit numbers ending in 5

Let me explain the easier method for squaring 3 digit numbers ending in 5 with an example:

Fun Numbers Part 2

37 is another fun number. 37 is a prime number and reversing the number 73 is also a prime number. If you multiply 37 with multiples of 3 see:

Fun Numbers Part 1

A number is a mathematical object used to count and measure. A notational symbol that represents a number is called a numeral but in common use, the word number can mean the abstract object, the symbol, or the word for the number. There are certain numbers, when used for some operations gives interesting results. It is fun exploring such numbers. If these interesting numbers are kept in our memory it makes calculation easy for many problems

MIND MULTIPLICATION of numbers close to 100

Here is a simpler method to find the product of 2 numbers  close to 100 by just mind calculation

Example 1 : Suppose you want to know 98 x 99

Step 1 :98 is 2 short of 100 so put2 below 98

     98 x 99
      2
Step 2: 99 is 1 short of 100  so put 1 below 99

    98 x 99
     2     1
Step 3: Multiply the 2 numbers put below
  2 x 1 = 2  this will so 02 will be the last part of the answer

Step 4: Subtract diagonally
     98-1 =97
    99 -2 =97
     this would be the first part of the answer so

98 x 99 =9702

Example 2 : 95 x 98

step 1 : 95 x 98
            5
step 2 : 95 x 98
            5      2
step 3 : 5 x 2 = 10

step 4 : 95 - 2 = 93
            98 - 5 = 93    
so answer of 95 x 98 = 9310