Vintage wooden school abacus - counting board unit tens in pearl school 1960-70

This charming vintage abacus is made of wood and metal. It dates from the 1960s and 1970s. It is a board with beads for learning to count and count units and tens. I note scratches from use and traces of its past life. It measures 20 X 16 cm. Perfect in a child's bedroom or in an entrance with a school-themed decor.