Sunday

February 1, 2015

February 1, 2015

Posted by **Jeff** on Thursday, January 17, 2013 at 3:40am.

- MATH -
**Reiny**, Thursday, January 17, 2013 at 10:05amlook at powers of 7

7^0 ends in 1

7^1 ends in 7

7^2 ends in 9

7^3 ends in 3

7^4 ends in 1

7^5 ends in 7

7^6 ends in 9

etc.

So it repeats after 4 digits

If we divide the exponent by 4, all we have to do is look at the remainder, and match it with the exponents of the above chart.

eg. for 7^10 (your calculator can still do that one)

it ends in????

10÷4 leaves a remainder of 2 and from the above, for an exponent of 2 our number should end in 9

10^7 ends in a 9 !!!

So...

for 7^76 , dividing 76 by 4 leaves a remainder of 0

so 7^76 end in 1

**Answer this Question**

**Related Questions**

maths - In a tree digit number, the tens digit is thrice the units and the ...

word problem - the different between the digit of a two digit number is 1, the ...

word problem - the different between the digit of a two digit number is 1, the ...

maths - in a two digit number the unit digit is one more than twice the ten's ...

mathematics - In a two digit number,the tens digit is 3 more than the inits(ones...

algebra/math - If the unit’s digit of a two-digit number is 6 more than the ten’...

math - The number uses every number 0-9 the numbers are used only once the ...

math - a 2 digit number, divisable by 6, the 10s unit is 1/2 of the digit unit

singapore math - My 3rd grade son get this math problem. It states that John ...

math - need help with math word problems. just don't understand. What is the ...