Considering the provided information in the given question, we have :
- Total seashells Saniyah have = 9
- Number of seashells Saniyah gave to her sister =
of total.
We need to find how many seashells did Saniyah have left.
⇒ Number of seashells Saniyah have left = Total seashells – Number of seashells she gave to her sister
⇒

⇒

⇒ Left seashells = 9 – 3
⇒ Left seashells = 6
Therefore, Saniyah have left
.