are fish invisible

well on but they might as well be scientist just realized there are at least 10 time more fish  in the ocean than we  thought. The fish are hanging out  it the twilight zone of the ocean 500- 3,200 feet  below the waves . They come closer  to the surface to it night so scientists  used sonar sending a sound through the water and seeing if it bounces off fish to estimate how many fish there were. That when there started uncovering some very fishy numbers. if you're  counting fish and have counted up to 6 what number  do you say next. 7. If  you expected to find 5 fish and found 10 more then that how many fish did you  find 50 fish.  If a sonar ping travels 200 feet  from the ocean surface to the  floor bounce off the floor and comes  straight back up to the surface how many feet does it travel. 400 feet 200 down +200 up. if there 95 hinder fish for every 5 fish  you see and you see 15 fish how many hidden fish must there be 5 hidden fish 15 visible fish means there are 3 sets of 95 hidden fish  because 15/5= 3.  for called bedtime math