Hello! I'm quite new to Perl 5, and often struggle with the concept of references (as other languages I've dabbled in do not use these)

I'm going through a Ruby OOP book that I like and am trying to use the experimental 'class' features to familiarize myself with the language more (I'm learning it to work on a project with a friend)

In the following snippet, the code for the ratio method was working fine. However, with the addition of the gear_inches method, I get a cryptic (to me) error: Can't use string ("26") as a symbol ref while "strict refs" in use at gear1.pm line 15.

This seems to imply that when I create the new class instance at the end, the rim parameter value of 26 is interpreted as a symbolic reference when the 'gear_inches' function is called. Upon reading up on symbolic references: https://perldoc.perl.org/perlref#Symbolic-references

It seems that Perl is saying that '26' (the value of the scalar) is taken to be the name of a variable. I have no idea how this could possibly be given the simplicity of the code. Every problem that produced an error message I couldn't make sense of previously involved de referencing, a concept with which I've not previously dealt. I guess this is probably also that somehow (lol?) Thank you for your time! 
use v5.40.0;
use experimental 'class';

class Gear {
    field $chainring :param :reader;
    field $cog :param :reader;
    field $rim :param :reader;
    field $tire :param :reader;

    method ratio {
        return $chainring/$cog;
    }

    method gear_inches {
        return ratio * $rim + ($tire * 2);
    }

}

say Gear->new(chainring=>52, cog=>11, rim=>26, tire=>1.5)->gear_inches
+;

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In reply to Using perlclass 'methods' by drudgesentinel

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