We've made a rainbow craft similar to this once before, I originally got the idea from No Time for Flashcards. But this time I just wanted to subtly add the letter A to the craft so we could reinforce that Arcoiris starts with A. So, I just wrote lots of A's on construction paper and cut it up before having her glue it on the colored lines of the rainbow.
Gluing the little pieces of paper turned out to be a really good fine motor skill builder. She had fun!
See all the other Spanish/English alphabet crafts we've done!