Use yath instead of prove.

$ cat example.t
use Test::More;

subtest foo => sub {
  ok 1;
  ok 2;
  ok 3;
};

subtest bar => sub {
  ok 4;
  ok 5;
};

done_testing;

$ yath example.t

** Defaulting to the 'test' command **

( PASSED )  job  1    example.t

                                Yath Result Summary
----------------------------------------------------------------------
+-------------
     File Count: 1
Assertion Count: 7
      Wall Time: 0.36 seconds
       CPU Time: 0.53 seconds (usr: 0.16s | sys: 0.01s | cusr: 0.31s |
+ csys: 0.05s)
      CPU Usage: 146%
    -->  Result: PASSED  <--
[download]

Note assertion count is seven: five individual assertions plus the two subtest blocks grouping them.

Yath is just a better test runner in so many ways. If you have a large test suite, you can set it to send a notification by email or by Slack when the test suite has finished running. You can add # HARNESS-DURATION-LONG comments to long-running tests then run yath --no-long to only run short/medium tests. You can create a JSON log of a test run, then run yath --rerun-failed to just re-run the tests that failed last time. And the default output is prettier.