Let's convert the 8700mL to L so that we can use the information in the problem more easily and swiftly. Since 1000mL is the same thing as 1L, we can say that 8700 mL of tomato soup is equal to 8.7L of tomato soup.
First, we know that he removed 1.6L to put in his kids' lunches. Thus, we now have 7.1L remaining. Now, we know that he froze half of this. Half of 7.1L is 3.55L (7.1L/2 = 3.55L), which means that he froze 3.55L. Finally, we will need to convert this back to mL. Since 1L is equal to 1000mL, we can multiply 3.55 by 1000 to get 3550mL.
