Sure, let's break down the problem step by step.
1. Understand the conversion:
- We know that Crystal had a cup of whipped cream.
- By standard conversion, 1 cup is equivalent to 8 ounces.
2. Crystal's whipped cream:
- Since Crystal had exactly 1 cup, she had 8 ounces of whipped cream.
3. Willow's whipped cream:
- Willow had 1 ounce less than Crystal.
- So, if Crystal had 8 ounces, then Willow had \( 8 \text{ ounces} - 1 \text{ ounce} = 7 \text{ ounces} \).
Therefore, Willow had 7 ounces of whipped cream.