Cut out balloon shapes in a variety of colors. Use these shapes to create a border around your bulletin board. Post a square of each color in the middle of the board, then pin pieces of yarn from each balloon to the colored square it matches.
Spell out "carnival" at the top of the board. Find pictures of objects related to the carnival that begin with each letter. Pin the pictures in random spots on the board and ask children to find the pictures that match each letter.
For the first week of school, post a drawing of a Ferris wheel and write each child's name on one of the seats. Allow each child to find her name on the board. Reward children throughout the week for raising their hands or answering questions correctly by putting a star on their named seat.
Post pictures of groupings of carnival-related items. Put up pictures of three hot dogs, five cotton candy, one clown or two tents. Use the pictures in lessons on learning numbers.