Square of a Number

Square of a number having 5 at its one’s place and 2 or more digits at its ten's, hundred's,......etc. place is equal to 25 followed by the product of the number of the remaining digits and the number exceeded by 1.

You may write the products in one line.

a)         5 5         (b)         6 5         (c)         7 5         (d)         1 0 5

         x 5 5                    x 6 5                    x 7 5                   x 1 0 5

      ______                 ______                 ______                 _______



           (e)         2 0 5         (f)         3 4 5         (g)         9 9 5

                     x 2 0 5                    x 3 4 5                   x 9 9 5

                 ________                  ________               ________

Check answers:

(a) 3025

5 x 6 = 30


(b) 4225

6 x 7 = 42


(c) 5625

7 x 8 = 56


(d) 11025

10 x 11 = 110


(e) 42025

20 x 21 = 420


(f) 119025

34 x 35 = 1190


(g) 990025

99 x 100 = 9900

Related Concept

● Patterns and Mental Mathematics

● Counting Numbers in Proper Pattern

● Odd Numbers Patterns

● Three Consecutive Numbers

● Number Formed by Any Power

● Product of The Number

● Magic Square

● Square of a Number

● Difference of The Squares

● Multiplied by Itself

● Puzzle

● Patterns

● Systems of Numeration

4th Grade Math Activities

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