Volume = length times width times height
Volume = 40 mm times 25 mm times 2mm
Volume = 2000 cubic mm (If you want to write it in a different unit, 2 cubic meters)
One cubic mm = 0.0005 ounces
2000 cubic mm = weight of one cubic mm times 2000
2000 cubic mm = 0.0005 times 2000
2000 cubic mm weighs 1 ounce
