According to the square number definition, they are the numbers that are multiplied by themselves. In other words, if a natural number is multiplied by itself, it is known as a square number. For example, 2 multiplied by itself (2×2) is a square number. When we multiply two equal integers by each other, the result of that ticket is basically a perfect square. Square numbers cannot be negative because if a negative number is multiplied by the same negative number it results in a positive number. Hence, square numbers are always positive.
Square numbers are named after a square because they form an area of a square. Imagine you have 9 items of 3 different categories. If we arrange it into a grid of 3 columns and 3 rows (3*3=9) placed vertically and horizontally, the grid will form a square.
Squaring Decimals
Just like squaring whole numbers (integers) is easy, it is also very easy to square decimals and both are done in the same way.
For example, 1.53 x 1.53 = 2.3409
7.19 x 7.19 = 51.6961
Properties of Square Number

Property 1 Square numbers will always end with the digits 0,1,4,5,6 and 9. For example 9,14,25,81,100 are perfect squares whereas numbers like 17,22,83 are not perfect numbers.

Property 2 A square number always contains an even number of zeros at the end and numbers containing an odd number of zeros cannot be square numbers. For example, 1600 3600 2500 square numbers whereas 1000, 250,160 are not square numbers.

Property 7 Square root of a square number is a whole number. For example, the square root of 441 is 21 so your 441 is a square number. If the square of a number is a decimal of a fraction number then the number is not a perfect square. For example, √56=7.48, so your 56 is not a perfect square.
1²=1
2²=1+3
3²=1+3+5
4²=1+3+5+7 and so on.
(2m,m²1,m²+1) is a Pythagorean triplet.
Below is the Table of Square Numbers From 1 to 100:
1²=1 
21²=441 
41²=1691 
61²=3721 
81²=6561 
2²=4 
22²=484 
42²=1764 
62²=3844 
82²=6724 
3²=9 
23²=529 
43²=1849 
63²=3969 
83³=6889 
4²=16 
24²=576 
44²=1936 
64²=4096 
84²=7056 
5²=25 
25²=625 
45²=2025 
65²=4225 
85²=7225 
6²=36 
26²=676 
46²=2116 
66²=4356 
86²=7396 
7²=49 
27²=729 
47²=2209 
67²=4489 
87²=7569 
8²=64 
28²=784 
48²=2304 
68²=4624 
88²=7744 
9²=81 
29²=841 
49²=2401 
69²=4721 
89²=7921 
10²=100 
30²=900 
50²=2500 
70²=4900 
90²=8100 
11²=121 
31²=961 
51²=2601 
71²=5041 
91²=8281 
12²=144 
32²=1024 
52²=2704 
72²=5184 
92²=8464 
13²=169 
33²=1089 
53²=2809 
73²=5329 
93²=8649 
14²=196 
34²=1156 
54²=2916 
74²=5476 
94²=8836 
15²=225 
35²=1225 
55²=3025 
75²=5625 
95²=9025 
16²=256 
36²=1296 
56²=3136 
76²=5776 
96²=9216 
17²=289 
37²=1369 
57²=3249 
77²=5929 
97²=9049 
18²=324 
38²=1444 
58²=3364 
78²=6024 
98²=9604 
19²=361 
39²=1521 
59²=3481 
79²=6241 
99²=9081 
20²=400 
40²=1600 
60²=3600 
80²=6400 
100²=10000 