How to Test an Adding Machine

Adding machines are similar to calculators.

Adding machines are very similar to calculators, except that there's a sheet of paper that comes from the top of the adding machine which shows all the facts and figures input so far. These machines aren't as common as standard calculators, but the ability to back check all of your input figures is a handy feature that only a select few people will use on a regular basis. Testing an adding machine to make sure that it works properly is a rather simple activity.

Things You'll Need

• Adding machine

Instructions

1. Work out an equation longhand. This equation could be something simple, such as 1+2=3, or something slightly more complicated, such as determining a percentage. Make sure that your equation is correct before you input it into your adding machine.

2. Type the equation into the adding machine and check the result. Punch in a number, the necessary mathematical sign, the next number and then the equals sign. Each time you hit a sign rather than a number, the paper at the top should spin out with the numbers you input typed on it. When you input the formula, type it from left to right.

   If there's a discrepancy, check both results, performing both calculations again if necessary. Look over the paper record generated by the adding machine. If the error is user-generated, type the equation in properly and check that result. If an error persists, you will know your machine is not working properly.

3. Check each function of the adding machine in turn. Check each key in the adding machine to make sure that it works properly. Read the manual if you're not familiar with all the separate functions of your adding machine.

Tips & Warnings

• The above steps can be used to test computer generated adding machines as well.

References

• Key Got: How to Use an Adding Machine