One day, 2000-500=<<2000-500=1500>>1500 cans of food were left.
It was then restocked to 1500+1500=<<1500+1500=3000>>3000 cans.
1000*2=<<1000*2=2000>>2000 cans were taken the next day.
3000-2000=<<3000-2000=1000>>1000 cans were left.
It was restocked once more to 1000+3000=<<1000+3000=4000>>4000 cans of food.
Carla gave away 500+2000=<<500+2000=2500>>2500 cans of food.
#### 2,500