my $var = "Testing 1 2 3";

my $no_interpolation = 'Var = $var';
# result: Var = $var
my $interpolate = "Var = $var"
# result: Var = Testing 1 2 3

my $escape = "Get lots of \$\$\$ by pressing Shift+4 many times \%-)";
# result: Get lots of $$$ by pressing Shift+4 many times %-)

# (note: this money-making technique is designed for German keyboards :) )