Abacus

**Abacus - beads arranged on a frame; used for counting or calculating from []**  Interactive sites for teachers & students to use [|1.] the links are excellent - history, interactive abacus, how to operate an abacus [|2.] ...especially this link [|3.] an excellent interactive abacus [|4.] this is an excellent youtube video of how to make an abacus - includes all materials & tools needed