Your code doesn't use the unit's worth at all.

Please say which language you're using when asking for help, and use markdown tags to format your code or it is very discomfortable to read, see: how-to-format-code-in-markdown.

This kata has been solved more than 16000 times so it's more likely your code has a problem rather than tests. Maybe this can help you debugging: Troubleshooting Your Solution.

Read the description more carefully. Each unit has a different strength, you need to take this into account.