7.12. Output

>perl examples/bc/bc5.pl
#     You named your test '30'.  You shouldn't use numbers for your test names.
#     Very confusing.
ok 1 - 30
ok 2 - 23+7
not ok 3 - 11+1
#     Failed test (examples/bc/bc5.pl at line 20)
ok 4 - 2*21
1..4
# Looks like you failed 1 tests of 4.

The first entry in the @sets array is not good as the operation will be executed by Perl and not by bc.