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?
answer: 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