1. A reading device for teaching or learning reading, comprising: (A) a two-layer structure containing: (a) first layer, (b) an opposite second layer, (c) viewing slots formed in corresponding portions of the first and second layers, and (d) a hollow pocket defined between the first and second layers; wherein: (1) the first layer has printed on a front face thereof a letter/image chart containing (i) all the letters of the alphabet, (ii) all or substantially all letter combinations composed of successive letters having a single sound (referred to herein as “single-sound letter combinations”); (iii) proximate to each letter and letter combination, an image of an object the name of which is indicative of the sound of the letter or letter combination; and (iv) a number proximate to each letter and single-sound letter combination on the letter/image chart; and (2) the second layer has printed on a back face thereof a numerical listing of the names of the objects represented by the images on the letter/image chart; and (B) a flat card having a front face which is blank and a back face which has printed thereon one or more sample words or sentences, the flat card being disposed for insertion into the hollow pocket defined between the first and second layers.