Old mechanical manual counting machine for arithmetical calculations.
Financial paperwork. Unrecognizable person performs arithmetic operations calculates costs per month
Close-up of water bottle, abacus and bunch of paper on the desk in school
Montessori material to present addition operations in schools.
Vintage abacus
A young boy lost in thought under chalkwritten numbers on a blackboard
Side view of a Caucasian schoolgirl learning mathematics with an abacus in the classroom at school
Child counting numbers on fingers
Cute boy learning mathematics with abacus at table
Front view of cute African American boy learning mathematics with abacus in a comfortable home
abacus calculating with beads on wooden rainbow abacus for number calculation. Mathematics learning
Detail of the colored beads of a wooden abacus, elementary educational material.
Bars for counting and doing arithmetic operations on a montessori material.
Detail of the colored beads of a wooden abacus, elementary educational material.
African American boy learning mathematics with abacus on dining table in kitchen at home
Boy learning mathematics with abacus at desk in classroom at elementary school
Schoolboy learning math with abacus at desk in a classroom
Schoolboy learning math with abacus at desk in a classroom at elementary school
Cute schoolboy learning math with abacus at desk
Boy learning math with abacus in a classroom at elementary school
Schoolboy learning math with abacus at desk in classroom at elementary school
Beads to learn to count in a montessori classroom on aged wood.
Thoughtful mixed-race schoolboy learning mathematics with abacus in a classroom at elementary school
Beads to learn to count in a montessori classroom on aged wood.
Beads to learn to count in a montessori classroom on aged wood.
Focused mixed-race schoolboy learning mathematics with abacus in a classroom
Boxes with beads to learn to count in a montessori classroom on aged wood.
Boxes with beads to learn to count in a montessori classroom on aged wood.
Boy learning mathematics with abacus at desk in classroom at elementary school
Schoolgirl learning mathematics with abacus in classroom at school
