Here are 18 cards I made for Reading RTI. The object of this activity is for the student to figure out which letters are missing from the section of the alphabet and then use letter tiles or magnetic letters to fill in blank. Each page has 3 alphabet strips on it. I simply printed out the 6 page file onto cardstock, cut the strips apart and laminated them for durability. Voila`! For RTI, I give each child an alphabet strip and he/she has to dig through the letter tiles to find the letters that are missing from the sequence.