This article is used to find out the square of a number in a short period of time compare to normal maths. It increase the speed of your calculations. The answer obtained by multiplying a number by itself is the square of that number.
Example :- 6×6= 36 which is the square of 6.
8×8= 64 which is the square of 8.
1. Square of numbers ending in 5 :-
Example 1-:
352 = ?
Step 1:-Multiply the first part by the first
part plus 1:
3×(3+1) =3×4 =12
Step 2:-Write the number 25 next to the
result from step 1:
352 = 12_25 = 1225
Example 2-: (in 3 digits)
1252 = ?
Step 1:-Multiply the first part by the first
part plus 1:
12×(12+1) =12×13 =156
Step 2:-Write the number 25 next to the
result from step 1:
1252 = 156_25 = 15625
Example 3-: (in decimal numbers)
9.52 = ?
Step 1:-Multiply the first part by the first
part plus 1:
9×(9+1) =9×10 =90
Step 2:-Write the number 25 next to the
result from step 1:
9.52 = 90_25 = 90.25
2.
The second method of doing squares is from this
formula. Formula means
by adding and subtracting. A square of one more or one less of a number (with unit digit
zero) can be easily extracted by this method. In the same way, the square of a number can be known
or can be easily known. Square of one less or one more of that number will also
be found by this method.
Example 1 :- Help of 402=1600, We find square of 39 and 41.
392 = 402-40-39=1600-79=1521
412 = 402+40+41=1600+81=1681
Example 2 :- Help of 452=2025, We find
square of 44 and 46.
442 = 452 -45-44 = 2025-89 = 1936
462 = 452+45+46 = 2025+91 = 2116
Example 3 :- Help of 4002=160000, We find square
of 399 and 401.
3992 = 4002-400-399 =160000-799
= 159201
4012 = 4002+400+401 = 160000+801
= 160801
3. Squaring number near base :-
When number is more than base
Example 1-:
1072 = ?
Step 1 :- Find the difference between given
number and base
Difference = 107-100=7
Step 2 :- Now add given number and difference
107+7=114
Step 3 :- Find the square of difference
72=49
Step 4 :- Write the result of step 3, next to
the result from step 2:
1072 = 114_49 =11449
Example 2-:
1122 = ?
Step 1 :- Find the difference between given
number and base
Difference = 112-100=12
Step 2 :- Now add given number and difference
112+12=124
Step 3 :- Find the square of difference
122=144
Step 4 :- Write the result of step 3, next to
the result from step 2:
1122= 124_144 =124+1_44=12544 (because base have 2 zeros)
Example 3-:
10112 = ?
Step 1 :- Find the difference between given
number and base
Difference = 1011-1000=11
Step 2 :- now add given number and difference
1011+11=1022
Step 3 :- Find the square of difference
112=121
Step 4 :- Write the result of step 3, next to
the result from step 2:
10112= 1022_121 =1022121
When number is less than base
Example 4-:
972 = ?
Step 1 :- Find the difference between given
number and base
Difference = 100-97=3
Step 2 :- now subtract difference from given
number
97-3=94
Step 3 :- Find the square of difference
32=09
Step 4 :- Write the result of step 3, next to
the result from step 2:
972= 94_09 =9409
Note: 10,100,1000,10000 etc. are called base.
4. This forth method is commonly used for squares of two-digit numbers. Before learning this, the student needs good practice of multiplication and division.
Formula : (a+b)2 = a2+2×a×b+b2
Let first digit = a , and second digit = b
Example 1 :- 492
1st part 2nd part 3rd part
42 2×4×9 92
16 72 81
16 72 81
16 80(72+8) 1
16 80 1
24(16+8) 0 1
492 = 2401 is Answer
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