 John North in his time of God devotion says, search carefully for the things that matter. In those days, 10 silver coins were strung together and worn around the head by an engaged woman. It was like an engagement ring. It's obvious, Jesus says, if a woman loses one of the coins on that precious headpiece, she searches very carefully until she finds it. Remember that in verse two, the Pharisees were grumbling at how much time Jesus was spending with sinful people. Jesus uses the story to say, isn't it obvious?