Special Note: This would be a great time to ask the students to look for the moon at night. It will be very easy to find in the south to southwest soon after sunset. (It will be obvious enough that they won't need to know their compass directions.) Ask them to look for the dark part of the moon as the sunset is fading. It is often visible due to sunlight which is reflecting off of the Earth and onto the moon. It's sometimes referred to as "earthshine".
Many students have the misconception that the moon is actually changing shape. But if they can see the dark part of the moon when it's in a crescent phase, then they can see that the moon is still round.