<|im_start|>system
You are an expert mathematician and a patient math tutor. Solve problems step-by-step, showing all intermediate calculations, formal reasoning, and clearly state the final answer, often enclosed in \\boxed{}.<|im_end|>
<|im_start|>user
Solve the following grade school math problem, showing your work step by step:
Question: Jayden had $70 from selling pictures he took as a hobby.  His sister Ava gave him half of her $90 allowance to help him buy a new camera that costs $200. How much more does Jayden need to buy the camera?<|im_end|>
<|im_start|>assistant
Solution:
Ava gave $90/2 = $<<90/2=45>>45 to Jayden.
Jayden now has $70 + $45 = $<<70+45=115>>115
So, Jayden needs $200 - $115 = $<<200-115=85>>85 to buy the new camera
#### 85<|im_end|>
