Question 749882
is it each balloon holds 265 CUBIC millimeters?
ok, I assume each balloon holds 265 cubic millimeters

the volume of a cube is V=s^3

our cube has 1 meter sides so V=1^3=1 cubic meter

now there are 1*10^9 cubic millimeters in a cubic meter so there are

1*10^9 / 265 cubic millimeters = 

3.77 * 10^6 balloons are filled