What is unit digit?

The unit digit refers to the digit on the rightmost side of a number. It is also referred to as the ones place, as it represents the value of a single unit in the given number.

The unit digit is significant for many calculations and patterns. It plays a crucial role in determining divisibility rules, cyclicity of numbers, and various arithmetic operations like addition, subtraction, multiplication, and division.

In terms of divisibility rules, the unit digit of a number helps determine if it is divisible by certain factors. For example, a number is divisible by 2 if its unit digit is even (0, 2, 4, 6, or 8) and is divisible by 5 if its unit digit is either 0 or 5.

The unit digit also plays a significant role in determining the cyclicity or repetition pattern of numbers. For instance, for powers of 2, the unit digit follows a cyclical pattern (2, 4, 8, 6) and for powers of 7, the unit digit follows a cyclical pattern (7, 9, 3, 1).

When performing arithmetic operations, the unit digits of the numbers involved can help in quickly determining the unit digit of the result. For addition and subtraction, the unit digit of the sum or difference solely depends on the unit digits of the numbers being added or subtracted. Similarly, in multiplication, the unit digit of the product is obtained by multiplying the unit digits of the numbers being multiplied.

In summary, the unit digit plays a crucial role in divisibility rules, determining cyclicity, and performing arithmetic operations. It provides valuable information and helps in various calculations and patterns.