A method of teaching basic arithmetical calculations is embodied in a novelty electronic graphic calculating device having a user interface for displaying method steps. The method involves displaying two or more collections of individual icons associated with two or more operands; selecting an arithmetical operation to be performed on the two or more operands; regrouping the individual icons into a collection of individual icons associated with an answer to the operation on the operands; and, displaying the collection of individual icons associated with the answer in sets of ten icons. The method permits visual regrouping and carry-over for teaching and learning mental computation of the four basic arithmetic skills of addition, subtraction, multiplication and division.