Question

What will be the unit digit of the square of the given number $5125$?
A). $0$
B). $1$
C). $5$
D). $9$

Answer 1

Hint: We will take the square of the given number $5125$ and from the squared number we will get the digit in the units’ place of that number. Every digit in a variety of devices represents an integer. As an instance, in decimal, the digit "$1$" represents the integer one, and within the hexadecimal system, the letter "a" represents the number ten.

Complete step-by-step solution:
The number $abcd$ in number system is expressed as

Number	$a$	$b$	$c$	$d$
Place	thousands	hundreds	tens	units

The number is $5125$.
Taking the square of the number:
$5125 \times 5125$
Multiplying the number by itself,
$ = 26265625$
Therefore, the square of $5125$ is $26265625$.
The last digit of a number before decimal is the unit’s place.
In the unit’s place we have the number $5$.
The correct option is option C. $5$.

Note: If we were asked to find the ten’s place of the number $26265625$ then it will be $2$ and the hundred's place is $6$and so on. Hence inside the positional decimal machine, the numbers zero to nine may be expressed using their respective numerals "zero" to "nine" inside the rightmost "devices" function. The range $12$ can be expressed with the numeral "$2$" in the unit’s position, and with the numeral, "$1$" in the "tens" role, to the left of the "$2$" whilst the number $312$ may be expressed with the aid of three numerals: "$3$" within the "hundreds" role, "$1$" inside the "tens" role, and "$2$" within the "units" role.