Have your child draw a picture of our flag. If he/she is unsure of what it looks like, then help him/her draw it. Then, talk about each part and its significance (the 50 stars for the 50 states, 13 stripes for the original 13 colonies, red for hardiness and valor, white for purity, blue for perseverance and justice). Once you have taught what you know about the flag, have your child write about the flag. Writing is such a great way to fuse the information into your mind. You will then have a great piece of art-work and language learning to put up on a wall or refrigerator. When your child is writing about the flag, you can work on retelling information, grammar, spelling, and writing complete sentences. The more details you expect could be directly related to your child's age and skill level. He/she can include historical information (when was it created, who created the first flag) and significance of the elements (colors, stars, and stripes).
Now when your child sees the flag on the TV as he/she is watching the Olympics or flying on a flagpole, he/she will know so much about the United States of America and the symbol that we have chosen to represent this great nation.