Abstract: A teaching device, for use in a classroom, comprising a hand-held size calculator adapted to normally include a display for showing the numerical output of the calculator, and adapted to include a face plate having a plurality of keys which are arranged in a particular pattern and which bear indicia indicating the calculator function of the keys. The calculator does include a circuit for producing a signal in response to depression of the face plate keys of the hand-held size calculator. The teaching device further includes an enlarged keyboard including a plurality of enlarged keys arranged in a key pattern simulating the face plate keys of the hand-held size calculator, and indicia on the enlarged keys simulating the indicia on the faceplate keys of the hand-held size calculator. The indicia is readily readable anywhere within the classroom. The keyboard also includes a plurality of switches responsive to depression of the keyboard keys.

Abstract: A display holder to assist in the selection of mats and frames for a picture. The picture is placed on a flat mounting board. Mat corners are properly positioned at the corners of the picture by being received in step-like offsets formed in ledges extending along corners of the mounting board. Frame corners fit over the top of the ledges. Clamps secure the mat corners and picture in position. The mounting board is formed in two telescoping sections or in two sections slidably mounted on a base by dovetail connections to permit adjustment of the longitudinal dimension of the mounting board.

Abstract: A relatively low-cost, portable, stand-alone visual training system interactively displays two dimensional representations of elongated objects on a viewing screen. An operator observes the elongated object and through an input device, such as an alpha numeric keyboard, divides the object into segments and allocates the segments according to preselected criteria. The results of the operator's decision are then calculated in a programmed data processor and compared visually with a predetermined result which is stored in memory for the particular object.

Abstract: A collection of modelling elements having distinct forms and changeably interengageable for assembly to one another. Each element includes information stores and signalling paths via which said stores are connected in an information transfer network to engaged elements. The information store contents are machine readable via an entry to the network and the way in which the elements have been assembled is detectable from the machine readable contents. The elements can represent constructional features, such as parts of a building, and the physical characteristics of a building of desired appearance represented by a particular assembly can be worked out and displayed from the way in which the representational elements have been assembled.

Abstract: A three dimensional toy having a base member showing a housing development with structural profile members mounted thereon which are secured by profile locking elements for constructing elevations of roadways, lots and surrounding terrain. The profile members and locking elements also serve as retaining walls for soil which, when shaped to conform to the contours of the profile members and locking elements and provided with living plants defines the topography of a living housing development.