We've worked on letter of the day/letter of the week before and here's the list of activities that I came up to go with each letter...
A Activities
Alphabet Puzzles
Airplanes
Automoblox
B Activities
Bubbles
Balloons
Baby Dolls
Butterflies (clothespins/tissue paper)
Books
Blocks
Balls
Baking
Balance Beam
Bingo
Ballet
C Activities
Cloud Dough (8 cups flour/1 cup cooking or baby oil)
Crayons/Coloring Books
Circus (make your own)
Carnival (play carnival games)
Catapult (experiment with different objects from around the house)
Caterpillars (search for them outside, read the Very Hungry Caterpillar)
Cooking (real or pretend)
Colors (color mixing with paint or food coloring in water)
D Activities
Dinosaurs (or dino dig -- sandbox with dinosaurs hidden inside)
Dollies
Doilies (art projects with doilies from the Dollar Store)
Duplos
Dough (various kinds)
E Activities
Egg Hunt
Emotions
Exercise
Experiments
Easy Bake Oven
F Activities
Face Painting
Finger Painting
Flowers (grow your own, paint, color)
Food (play food, grocery store etc.)
Farm
Fishing Game
Fort (build your own in the living room with blankets and pillows)
Family (create a family portrait or a family tree)
Fingerprint Animals
G Activities
Games
Grocery Store
Gliding (pretend you're ice skating by using plastic on the bottoms of your feet)
Goals (use soccer or hockey goals)
Glow in the Dark Fun
Gymnastics
H Activities
Hair Salon
Hide-n-go-Seek
Horses
Hats (play the silly hat game like on "Who's Line is it Anyways")
Hearts (cut out hearts from construction paper, learn about the human heart)
Health (visit a doctor's office, ready about your body)
Hunger (bring food to the hungry)
Happy (sing, "If You're Happy and You Know It")
I Activities
Igloo (make one out of snow, sugar cubes or Legos)
Imagination Station
Instruments
Ice Skating
J Activities
Jumping
Jokes
Jam (make your own)
Jelly Beans (have a hunt with pictures of Jelly Beans)
K Activities
Kicking
Karate
Kangaroos and Koalas (learn about Australia)
L Activities
Legos
Little People
Lemonade (make your own and have a Lemonade Stand)
M Activities
Measuring
Moon (moon bounce, learn to moonwalk)
Monkeys
Music
Movies
Mosaic
Magnets
N Activities
Nails (& Hammer)
Nail Polish
Noodles
Nest
Nocturnal Animals
Nature
Night
Numbers
Necklaces
O Activities
Obstacle Course
Outside
Origami
P Activities
Princesses
Pirates
Play-Doh
Puzzles
Puppets
Potato Heads
Paint
Potato Stamping
Playmobil
Patterns
Park
Picnic
Q Activities
Quiet Books
Quilting
Quest
Queen/King
R Activities
Roller Coaster
Rainbows
Royal Ball
Restaurant
Roller Skating
S Activities
Sand Box
Stickers
Stamps
Soap-Box Derby
Seasons
Sounds
Stencils
Scissors (cut Snowflakes)
Swing
Slide
Sledding
Swimming
T Activities
Tattoos
Trains
Trucks
Travel
Tent
Textures
Trampoline
U Activities
Umbrellas
Under the Sea
Unicorns (make horns for the top of your head)
V Activities
Vetranarian
Volcano
Valentines
W Activities
Water Play
Water Beads
Whales
Wedding
Wedgits
X Activities
Xylophone
X-Ray (make your own skeleton)
Y Activities
Yodeling
Yahtze
Z Activities
Zoo
Zippers
Zip-Loc Bags (fill them with paint or colored water)
