what number when multiplied times itself gives a product of 729

Question

I need lots of help figuring out how to do these.

Answer 1

You are looking for the square root of 729.

 

What number multiplied by itself gives us a product that ends in 9?

 

3(3) = 9 and 7(7) = 49, so our number ends in 3 or 7.

 

20(20) = 400 and 30(30) = 900, so it's between 20 and 30, so it's either 23 or 27.

 

729 is closer to 900 than 400, so I bet it's 27. Let's check.

 

27(27) = ?