To solve the problem, we can identify the operations involved as follows:
- Let \( x \) be the number of stickers Reann started with.
- Reann gives her friend half of her stickers, so she has \( \frac{x}{2} \) left.
- Her brother then gives her 8 stickers, resulting in \( \frac{x}{2} + 8 \).
- She ends up with 12 stickers, which gives us the equation:
\[ \frac{x}{2} + 8 = 12 \]
- To solve for \( x \), we first subtract 8 from both sides:
\[ \frac{x}{2} = 12 - 8 \] \[ \frac{x}{2} = 4 \]
- Next, we multiply both sides by 2 to find \( x \):
\[ x = 4 \times 2 \] \[ x = 8 \]
Thus, Reann started with 8 stickers.
The operations needed to solve this problem are addition and division.
So the correct response is: addition and division.