how do you find 3rd/4th/5th/6th roots of numbers when it doesnt go in evenly?

Answer 1

There is an algorithm for finding the square root and cube root. I will use only part of those algorithm. to help with basically a guess and check method.
For a cube root of a number such as 4530000.
mark of in groups of three from the decimal.
45,300,000.
There will be a digit for each group. (You know the root will be a three digit number before the decimal.)
The first digit can be estimated by picking the number that is the hole number that when cubed is not greater than 45. (From the last group.)
4 is too large 4^3=64, so it is:
3,_,_. from here try three digit number beginning with 3.

Fourth roots is similar.
Mark off in groups of 4.

453,0000.
So it is 453 that you need to estimate the fourth root of.
5 is too large 4^4= 256.
So the fourth root will be a two digit number beginning with 4:
4_. (guess from here.)
For a fifth root mark off in groups of five from the decimal.
45,30000.
We need to estimate the fifth root of 45.
3 is too large. 2^5 =32.
So our fifth root is, a two digit number beginning with 2. or 2_.
This should get you started on any root you wish to estimate.

Answer 2

There is no easy way to do this. Of course you can use a calculator, but that begs the question. After all, someone had to figure out a mathematical method for doing this and then program that method into the calculator. As a previous poster stated, one of those methods uses logarithms:

to take the sixth root of 87, you would take the log of 87, then divide it by 6, then raise the answer to the 10th power (if the logs you are using are base 10)

Answer 3

this is if you have a TI-84 plus

type in 3, 4,5, or 6 which ever root your looking for
hit the math button
go down to number 5 and hit enter
then type in the number you are trying to find the root of
and enter again
should look like this
find the 3rd root of 29
3^x(square root symbol) 29
=3.07

Answer 4

Use a calculator or log tables.
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