The Abacus and the Numeral Frame Later Uses in the United States

By the mid-twentieth century, numeral frames were used less often in classrooms in the United States, but sold widely as an educational toy and less often as a device for the blind. Beads moved on rods or wires also remained part of classroom instruction. The Smithsonian collections include a “place value board,” a device in which plastic discs are moved along bent wires to teach elementary school students about units, tens, thousands and so forth.