Improved apparatus for teaching calculations to children and for like purposes

摘要

359,210. Teaching arithmetic. STEPHENS, S. W., 12, Bedford Road, Sandy, Bedfordshire. Oct. 22, 1930, No. 31757. [Class 146 (ii).] An abacus comprises a number of rods 5 detachably engaged at one end in holes 6 in a common support 2, the rods being adapted to carry a number of removable rings, beads, or the like 9 and having retaining knobs 14, while the support 2 forms the closure member or lid of the box 1 which accommodates the rods when not in use. The lid 2 is formed with longitudinal ribs 3 along the two long edges which engage channels in the box sides ; the ribs 3 are removed for a short distance at one end of the lid and this end is inserted in a narrow space 8 formed at one end of the box so that the ends of the ribs 3 abut against the upper edge of the box. The box is further formed with small compartments for containing the rings &c. and both these and the rods may be coloured ; a tray may also be supported inside the box to accommodate crayons and the like.