# Find unit digits

**Find unit digits end with the 2,3,7**

##### Q1. Find the unit digit of **(2517)**^{78}

^{78}

##### As we see the unit digit of given number is 7 so

7^{1} = 7

7^{2} = 7 * 7 = 4 9

7^{3} = 7 * 9 = 6 3

7^{4} = 7 * 3 = 2 1

7^{5} = 7 * 1 = 0 7

As we see in each multiplication we take the unit digit of previous calculated value and at the power of 5 we see that it repeats from power of 1.

= 78 / 4

= 2

we divide the power with 4 beacuse at the power of 4 we get the different unit digit . and as we see we get the reminder **2**.

So 7^{2} = 7 * 7 = 4 9

**Unit digit is 9 **

** For the number like (3261)**^{n} , (6515)^{n} , (2516)^{n} , (2480)^{n} where unit place digit are 1,5,6,0 respectivelly then unit digit will be same .

^{n}, (6515)

^{n}, (2516)

^{n}, (2480)

^{n}where unit place digit are 1,5,6,0 respectivelly then unit digit will be same .