An ABACUS can be used to teach the mathematical concept of:

• A. Addition and subtraction
• B. Fractions
• C. Multiplication
• D. Geometry

Answer: (A)

The key idea is using a concrete manipulable tool to model combining and removing quantities. An abacus uses beads on columns to represent numbers in a place-value system. Moving beads toward the central bar lets you add counts, and moving them away lets you subtract. This hands-on action makes how numbers come together (and how you regroup when needed) visible and tangible, which is exactly what you’re practicing when you add or subtract. For example, adding 7 and 5 in the ones column shows twelve beads, which can be regrouped into 1 in the tens column and 2 in the ones column, reinforcing place value and the concept of carrying. This direct, visual process is the most natural way an abacus supports arithmetic, so addition and subtraction is the best fit. While the tool can be used to explore other operations, the fundamental, everyday use centers on combining and removing quantities.