Perl sqrt, cube issue: 1 showing up after each line - shell

Question

I am having a tiny issue with a small perl script using arithmetic operators. After my cube root, and square root operators, a 1 shows up. I was testing this script on an openSUSE 42.1 VM.
I'm just not too certain what the 1 after each line is, I have tried looking it up, but am not too certain. I mainly script in bash, and ksh, so this perl syntax is a bit new to me.
Script:
#!/usr/bin/perl
# Provide a sum, cube of the sum, and square root of the sum of three set variables
# Set variables
$v1=10;
$v2=9;
$v3=8;
$val=$v1+$v2+$v3;
$cube=$val ** (1/3);
$square= sqrt($val);
print "Sum of 10, 9, 8: $val\n";
print
print "Cube of Sum: $cube\n";
print
print "Square of Sum: $square\n";
print
print "Thanks for using this script!"

Answer 1

Your lines just saying
print
are not statements in themselves as they are not terminated by a ;. Instead they are part of statements of the form
print print "text";
The inner print has an argument of "text" and prints that, the outer print has an argument of print "text" and print the value of that, and when succesful print returns a value of 1 (perldoc only says it returns true, so don't rely it being 1) - so a 1 is printed.
If the point was to format your output nicely, you should explicitly print "\n".

Answer 2

As has been explained, half of your print calls are printing the return value of the following print statement because you are missing a semicolon at the end of the line to terminate the statement
Also, print on its own will print the value of the default variable $_, not a newline as you expected. You need to write print "\n"; to achieve what you intend
It's also very important to add use strict and use warnings 'all' to the top of every Perl program you write. You will also need to declare all of your variables using my
#!/usr/bin/perl
use strict;
use warnings 'all';
# Provide a sum, cube of the sum, and square root of the sum of three set variables
# Set variables
my $v1 = 10;
my $v2 = 9;
my $v3 = 8;
my $val = $v1 + $v2 + $v3;
my $cube = $val**( 1 / 3 );
my $square = sqrt($val);
print "Sum of 10, 9, 8: $val\n";
print "\n";
print "Cube root of Sum: $cube\n";
print "\n";
print "Square root of Sum: $square\n";
print "\n";
print "Thanks for using this script!\n";
print "\n";
output
Sum of 10, 9, 8: 27
Cube root of Sum: 3
Square root of Sum: 5.19615242270663
Thanks for using this script!
It's also worth pointing out that there's a construct called a here document that will let you do this more neatly and clearly. If you change those print statements to just one, like this, then the intention is clear and the output is identical to that of the original code
print <<END;
Sum of 10, 9, 8: $val
Cube root of Sum: $cube
Square root of Sum: $square
Thanks for using this script!
END

Answer 3

As Henrik states in his answer, the lines with print and no ; are the problem.
An alternate way to get Perl to print a blank line between the main lines of output is to add an addition new line character, \n, at the end of each of the print lines. The code would become:
#!/usr/bin/perl
# Provide a sum, cube of the sum, and square root of the sum of three set variables
# Set variables
$v1=10;
$v2=9;
$v3=8;
$val=$v1+$v2+$v3;
$cube=$val ** (1/3);
$square= sqrt($val);
print "Sum of 10, 9, 8: $val\n\n";
print
print "Cube of Sum: $cube\n\n";
print
print "Square of Sum: $square\n\n";
print
print "Thanks for using this script!"
The output is:
Sum of 10, 9, 8: 27
Cube of Sum: 3
Square of Sum: 5.19615242270663
By the way, your equation for calculating the cube of the sum calculates the cubed root. To calculate the cube of the sum you need,
$cube=$val ** (3);
Likewise, your equation to find the square of the sum is calculating the square root, not the square. To find the square of the sum you need to raise the sum to the power of 2.