You are playing with a pile of beads and notice if you put them in groups of 4 you have 3 beads left over, in groups of 5 you have 4 beads left over and in groups of nine you do not have any left over. What is the smallest number of beads. Left over
Look at the multiples of 9.
9, 18, 27, 36, 45
Which of those numbers meets the criteria?