Simeon drinks 64 fluid ounces of filtered water every day.  He used to drink this water in 8-ounce-servings.  But now, he drinks his water in 16-ounce servings.  How many fewer servings per day does it now take Simeon to drink his water than it used to?
In 64 fluid ounces, there are 64/8=<<64/8=8>>8 eight-ounce servings.
Using 16-ounce servings, Simeon now drinks 64 ounces in 64/16=<<64/16=4>>4 servings.
Thus, Simeon now drinks his water in 8-4=<<8-4=4>>4 fewer servings per day.
#### 4