Pick out letters. This can be done with one or several children. The instructor will gather the children around the box and the green mat, so that everyone is sitting within reach, and request that the kids pick different letters out of the box. They will not take turns, but everyone should look until someone finds the requested letter. Once the instructor feels that everyone is familiar enough with the letters, move on.
Select a three-letter word to start with. It should be something simple, like "bat," "dog" or "big." Try to start out with words that are completely unambiguous in their phonetic sounds, and avoid words like "cat," which can be confusing at first because the letters C and K often sound alike.
Say to the children, "We are going to build words. Let's make the word 'bat.' What sounds do you hear when I say the word 'bat'?"
Have the children make the sounds in the word and then find the appropriate letter to match the sound. For example, if a child makes the "b" sound, have him find the B in the box and place it on the mat. You will need to help with arranging the letters until the children are fairly familiar with the activity. Continue making sounds until the word has been built properly on the mat.
Repeat the word on the mat to the children. Make sure you pronounce the sound of each letter clearly and individually, then as a whole word, before replacing the letters in the correct boxes.
Move on to other words. You can continue with this lesson for some time if your day plan allows it. However, stop before the children become too distracted, as you will repeat the lesson with both new and previously used words in the days to come.