Teaching addition and subtraction with borrowing involves guiding students through the process of regrouping or "carrying" when a column exceeds ten or "borrowing" when a digit in a lower place value is larger than the one above it. In both written form and on the abacus, the concept remains the same: when the value in a place value column is too large to handle, we either move extra units to the next column (in addition) or take units from a higher place (in subtraction).
On the abacus, students move beads in a physical manner, visually representing the borrowing and carrying process. Just like when writing numbers, students adjust the values of each place value by shifting beads, reinforcing the same concept of redistributing numbers between columns. This visual and tactile approach on the abacus can make the abstract idea of borrowing and carrying more concrete for learners.
by Jerred Sonneborn
