Take a look at the sentence again:
My grandmother doesn't trust banks, so she has __________ money all over
the house. Once, I pulled an old Reader's Digest off a shelf and
found seven $100 bills stuck between the pages.
The sentence requires the past participle of hide, an irregular verb. Hidden is the past participle.
| Verb | Simple Present | Simple Past | Past Participle |
| hide | hide(s) | hid | hidden |
Hiden, the form you chose, is a spelling error. Before you continue, review the rules for irregular verbs.
Go back to the sentence to try again.