What will be the unit digit of the square of 678
Answers
Answer:
The unit digit of the square of 678 is 4
Step-by-step explanation:
The last digit (one digit) of the product you get when you multiply 678 by itself is the unit digit of the square of 678.
Rule Method
The unit digit of any square will never be 2, 3, 7, or 8. It can be only 0, 1, 4, 5, 6, or 9. Furthermore, the unit digit of the square of a number depends on its units digit. In other words, the unit digit of the square of 678 depends on 8, because that is the last digit in 678. Here are the rules:
Rule A) If the unit digit of a number is 0, then the unit digit of the square of that number is 0.
Rule B) If the unit digit of a number is 1 or 9, then the unit digit of the square of that number is 1.
Rule C) If the unit digit of a number is 2 or 8, then the unit digit of the square of that number is 4.
Rule D) If the unit digit of a number is 5, then the unit digit of the square of that number is 5.
Rule E) If the unit digit of a number is 4 or 6, then the unit digit of the square of that number is 6.
Rule F) If the unit digit of a number is 3 or 7, then the unit digit of the square of that number is 9.
The unit digit of 678 is 8, therefore Rule C applies, and the unit digit of the square of 678 is 4.
Answer:
4
Step-by-step explanation:
The square of 678 is 678×678 = 4,59,684
In the units place the digit is 4.
So 4 is the answer.