The child has been diagnosed with rickets. The child’s mother is educated about the importance of providing the child with 10 micrograms (400 International Units) of an oral vitamin D supplement each day. The child’s mother purchases over-the-counter vitamin D drops. The supplement is noted to contain 5 mcg of vitamin D in each 0.5 mL. How much of the supplement should the mother administer to the child each day? Record your answer using one decimal place.