One of the first things that children learn in preschool is colors. Children first learn the eight basic colors -- blue, black, brown, red, orange, yellow, green and white -- and then move on to more difficult colors. An easy way to teach a child the basic colors is to use colored cards. Repetition is important with a young child, so tell him the color, point to the card and ask him to say the color. Keep repeating the color until he seems to get it, then move on to the next color. Return frequently to the colors he just learned to reinforce the names. Some games and activities that will reinforce the colors a child has learned are using finger paints or coloring books and asking the child to tell you the colors she is coloring with. You can also play "I Spy" around the house, asking the child to find different colored objects.
Preschoolers are not too young to learn the alphabet and to expand their vocabulary. A fun game to help kids learn the alphabet is called "Xs & Os". Take a sheet of paper and mark a letter at the top of the page, then write the letter randomly around the paper with many other letters. Ask the child to circle all the letters that are the same as the one on top and to cross out the ones that are different. You can repeat the game with every letter of the alphabet.
The game "Vocabulary In A Box" helps children understand the names and functions of objects. Take a large box and make a big hole at the top. Place a bunch of different objects in the box. Ask the child to pull out an object and see if he knows what it is called and what it does. If the child does not know the object, describe it in terms he can understand until he comprehends the name and use of the object.
To aid in development of math skills, counting is the perfect starting point, and the game "Number Matchup" is helpful to learn counting. Take a stack of index cards and write numbers from one to ten -- or higher if the child can count higher than ten -- and place them on a table. With a corresponding number of cards, draw the same number of objects on each card, for example: one house, two trees, etc. Have the child match up the number cards with the matching objects cards.
Because preschool-aged children have active imaginations, you can teach them elements of science in a way that stimulates their imaginations in a game called "Inventions We'd Rather Not See". Ask a child to think of silly or crazy inventions that solve problems in his life. If he needs help waking up in the morning, what would he invent that is better than an alarm clock? Or what invention would keep the dog from getting water all over the house after it's washed. Once a child sees that his imagination can figure out answers to problems in everyday life, his ability to think in a scientific way will grow.