Since its introduction in 1888, when it was patented by Williams Burroughs, the adding machine with tape has been a staple in office environments. However, they have become a dinosaur in the modern office, since hand-held tiny calculators can be found at every turn. Using an adding machine with tape provides advantages that you can't get from a hand-held machine, though. First, it lets you check your work immediately. Second, you have a permanent dated record of your work. Third, if working with long rows of numbers, you can do a side-by-side comparison.
Insert a roll of tape into the machine by dropping it into the depression made for it and feeding it through the bars that will hold it in place. Align the tape with the inked keys.
Press number buttons to multiply and divide problems the same way as you would with any calculator.
Addition and subtraction are performed differently. To add or subtract any number, key in the number, then follow it with the key "+" or "-," depending on the function. Do this for each number you are adding or subtracting. When you get to the end of the column, press the "Total" key, which is sometimes marked with an asterisk, or "Subtotal," which has a diamond shape on its key, to get your answer.
Look for the additional keys on the machine. The key with the arrow pointed up is the paper advance key, which will allow you to add paper to your column of numbers without having anything printed on it. The key with the arrow pointed to the right will erase the last digit you've put into the machine. The "#" key will print a number on top of the tape without including it into the total. This is a useful key if you want to show a date on the tape. A key that reads "+0234F" is the decimal point selector key, which automatically defaults to two digits but can be adjusted to an infinite number. The key that has up and down arrows along with a fraction is how you select if you want figures rounded up or down when performing multiplication and division calculations. The other keys function in the same manner as a regular calculator.
Finish your column of numbers, then hit one of the keys marked with an "M," which will keep the values in the machine's memory either as a subtotal or a total.