Squares of numbers ending in 1 & 5 by Bhārati Kṛṣṇa Tīrtha

From Vidyalayawiki

A number, when multiplied by the number itself the product obtained, is called "Square of that number ". We will come to know the squares for numbers ending in a particular digit 5 , 1.

Squares of Numbers ending in 5[1]

To find the square of any number ending in 5 , the sūtra used is

एकाधिकेन पूर्वेण

" Ekādhikena Pūrveṇa "

" By one more than the one before "

Example : 352

Left Hand Side (LHS) Right Hand Side (RHS)
3 5
Previous digit of 5 in 35 is 3

one more than 3 is 4

Square of 5 = 25
3 X 4 = 12
12 25

Right hand side will always be 25

Answer : 352 = 1225

Example : 1352

Left Hand Side (LHS) Right Hand Side (RHS)
13 5
Previous digit of 5 in 135 is 13

one more than 13 is 14

Square of 5 = 25
13 X 14 = 182
182 25

Right hand side will always be 25

Answer : 1352 = 18225

Squares of Numbers ending in 1

The specific rule to be followed to find the square of a number ending in 1 is explained through the below examples.

Example : 312

Left Hand Side (LHS) Right Hand Side (RHS)
3 1

Step 1: RHS : will always be 1 as (RHS)2 , 12 = 1

Step 2 : Middle: double the previous part of the number ( LHS) which is 3 . 3 X 2 = 6

Step 3 : LHS : Square of the previous part of the number (LHS) which is 3. 32 = 9

Step 4: Put the above values in the below table.

LHS MIddle RHS
9 6 1

Answer : 312 = 961

Example : 612

Left Hand Side (LHS) Right Hand Side (RHS)
6 1

Step 1: RHS : will always be 1 as (RHS)2 , 12 = 1

Step 2 : Middle: double the previous part of the number ( LHS) which is 6 . 6 X 2 = 12

Step 3 : LHS : Square of the previous part of the number (LHS) which is 6. 62 = 36

Step 4: Put the above values in the below table.

LHS Middle RHS
36 12 1
36 Put 2 and carry over 1 1
36 + Carry over 1 2 1
37 2 1

Answer : 612 = 3721

Example : 4512

Left Hand Side (LHS) Right Hand Side (RHS)
45 1

Step 1: RHS : will always be 1 as (RHS)2 , 12 = 1

Step 2 : Middle: double the previous part of the number ( LHS) which is 45. 45 X 2 = 90

Step 3 : LHS : Square of the prev us part of the number (LHS) which is 45. Here the number ending in 5 we will use एकाधिकेन पूर्वेण sūtra

Left Hand Side (LHS) Right Hand Side (RHS)
4 5
Previous digit of 5 in 45 is 4

one more than 4 is 5

Square of 5 = 25
4 X 5 = 20
20 25

LHS : 452 = 2025

Step 4: Put the above values in the below table.

LHS Middle RHS
2025 90 1
2025 Put 0 and carry over 9 1
2025 + Carry over 9 0 1
2034 0 1

Answer : 4512 = 203401

See Also

1 और 5 से समाप्त होने वाली संख्याओं का वर्ग - भारती कृष्ण तीर्थ

References

  1. Singhal, Vandana (2007). Vedic Mathematics For All Ages - A Beginners' Guide. Delhi: Motilal Banarsidass. pp. 193–203. ISBN 978-81-208-3230-5.