As for the function that we added, the subtraction was increased by consecutive calculations of the addition.
As memo frames are classified in four (when included index, five) that you can write a memo in four frames neatly.
Only as for the addition and subtraction, consecutive calculations are possible.
Because you can calculate it in succession because there are two finders containing the number.
While you are in addition, subtraction,you can confirm it carefully and turn in checking.
This performs only a simple calculation, but is certain, and is quick, and practical use characteristics are plentiful.
This suits well to office worker, domestic housewife, and child who are weak in the calculation.