A better example is taking 1,000 shares with a $25k account. Since your buying power is typically 4:1, you can take a position up to $100k using leverage.
1% of your account is $250. This means 0.25/share on 1,000 shares.
The important part is to find a stop loss at a technical level, and figure out the per-share loss. This will determine the maximum share size you can take. Stop loss first, share size after.
Using the same numbers above, a 0.50 stop loss would mean taking 500 shares. And so on and so forth.
The 1% rule is a maximum. You can always risk less, but never more.
When I traded 100 share lots, I pretended that my account was $2,500. All risk management and daily goal/loss calculations were based off $2,500 and not the full size.