Easy Way to Multiply Big Numbers

Multiplication is one of the basic operation in mathematics and its symbolic representation is ‘’×’’. It is difficult while multiplying big numbers. So, we are going to use the easy for multiplying big numbers. Easy way is to split the numbers into smaller parts and then multiply with 5, 10 and then add the result to the multiplication of remaining parts, we get the answer. Let us see about easy way to multiply big numbers in this article.

Worked Examples for Easy Way to Multiply Big Numbers

Example 1 for Easy Way to Multiply Big Numbers:

Multiply the Number which Ends with 5:

How to square the number 85?

Step 1:

Take the number which is on the left of the given number. The left of the given number is 8.

Step 2:

Multiply the left of the given number 8 with its consecutive number 9.

Multiply 8 × (8 + 1) = 8 × 9 = 72

Step 3:

Then multiply the ending number with the same ending number 5 is 5×5 = 25.

Step 4:

Grouping the step 2 and step 3 results, we get 7225.

Step 5:

Hence, squaring the given number 85 is 7225.

Example 2 for Easy Way to Multiply Big Numbers:

Multiplying Big Numbers by 11:

How to multiply 986 by 11?

Step 1:

Multiply 986 × 11

Step 2:

The number 11 can be written as (10 + 1).

986 × (10 + 1)

Step 3:

Now multiply 986 by 10, we get 9860.

Step 4:

Multiply 986 by 1, we get 986.

Step 5:

Add the result of above two steps.

9860 + 986 = 10846

Step 6:

Hence, multiplying 986 by 11 is 10846.

Example 3 for Easy Way to Multiply Big Numbers:

Multiplying two Big Digit Numbers:

55 × 57

13 × 14

Solution:

a) 55 × 57

Step 1:

Split the multiplier into two parts.

(55) × (55 + 2)

Now, multiply 55 with 55 and 2 respectively and add both the results, we get the answer.

Step 2:

Multiply the first part 55 × 55, by using the multiplication concept of numbers end with 5.

Step 3:

Take the number which is on the left of the given number 55. The left of the given number is 5.

Step 4:

Multiply the left of the given number 5 with its consecutive number 6.

Multiply 5 × (5 + 1) = 5 × 6 = 30

Step 5:

Then multiply the ending number with the same ending number 5 is 5×5 = 25.

Step 6:

Grouping the step 4 and step 5 results, we get 3025.

Step 7:

Multiply the second part 55 ×2, by using the multiplication concept of numbers end with 5.

55 × 2 = 110

Step 8:

Hence, multiplying 55 × 57, we have to add the step 6 and step 7 results, we get the answer.

3025 + 110 = 3135

Step 9:

Hence, the solution for multiplying 55 × 57 is 3135.

b) 13 × 15

Step 1:

13 × (10 + 5)

Step 2:

13 × 10 = 130

Step 3:

13 × 5 = 65

Step 4:

130 + 65 = 195

Step 5:

Hence, the solution for multiplying 13 × 15 is 195.

Practice Problems for Easy Way to Multiply Big Numbers

1. Multiply the 788 by 11.

2. What is the value of square of 75?

Solutions:

1. 8668

2. 5625