iPhone Screenshots


'Adding Machine 10Key iPhone' behaves like a true '10 Key' or 'printing calculator' such as those made by Monroe, Casio, Sharp and others. A total is obtained by pressing the asterisk (*), operator entry is reversed, and percentages are obtained by multiplying and adding to a stream of numbers. PLEASE SEE THE 1ST FAQ BELOW.

Adding Machine features dual keypads with a total (*) key on either the left or right side (Sharp or Canon style).

Also. Review & edit numbers, add or delete lines. Save & retrieve paper tape files. Export paper tape files to iBooks©, Dropbox©, Email or your favorite printing utility (see the FAQs).

Try before you buy. Find our 'Adding Machine Lite' by Richard Silverman in the App Store.

==== Recent Press =====
Currently featured in iTunes "What's Hot" in the Finance Category for iPad.

Strategic Finance (Tools of the Trade): "If you're looking for a professional desk calculator that can give you full 10-key accounting functions with a tape you can name and save, edit, e-mail, or print, check out Interlocken's 10 Key Adding Machine app."

● Behaves the same as a '10 Key' adding machine.
● Export a PDF file to iBooks©, DropBox©, Email, or your favorite printing utility.
● Select from a menu of keypad sounds.
● 400 lines of paper tape history (full version)
● 3 display formats: fixed, fix+, float
● Save paper tapes to disk for later use.
● Correct numbers, add comments, add/delete lines
● Use your voice to dictate comments (iOS 7 and greater)
● Two keypads offer the 'total' key on the left or right (Sharp or Canon style)
● Comprehensive set of help screens.
● International number formatting (Settings -> General -> International -> Region Format -> select region).


Q1. What is the difference between 'Adding Machine 10Key iPhone' and 'Accountant Calculator' in the App. Store.?
A1. Both are single-column adding devices and both have iPad versions with full size 1:1 keyboards. '10 Key' behaves the same as a 10 Key Adding Machine with reversed operator entry while ‘Accountant Calculator’ supports the free chaining of +, -, x, /, %, √, 1/x and is easier to use if you are not familiar with how a '10-key' works.

You can also reference the following link:

Q2. Can I touch-type?
A2. Checkout the iPad version with large (1:1) keyboards and several aids for touch-typing.

Q3. How can I quickly clear the paper tape?
A3. The quickest way is to double-tap the calculator's large "i" action icon to the left of the calculator's LCD display.

Q4. How can I edit an incorrect number or add & delete lines from the paper tape?
A4. Touch any line of the paper tape to go into edit mode. Touch the side controls: Add Line, Delete Line. You can also edit numbers. Press Done to return to Calculator mode.

Q5. How can I have my 'total' key be on the right side?
A5. Press the checkerboard icon on the left side of the paper tape until the keypad you want is displayed. There are three to choose from.

Q6. Tell me about Email, Printing, and Exporting a Paper Tape.
A6. From the Export dialog, select from: Email, Print, Copy or Open-In. Email includes a pdf attachment. Print requires an AirPrint capable printer. Open-In will cause a menu of 3rd party Apps to appear that can receive a hardcopy of your paper tape; for example, iBooks, DropBox, and 3rd party printer Apps for Brother, HP, Epson, Canon and more. With these print directly to a network reachable printer (even if it is NOT AirPrint capable).

What's New

Version 6.14k

Updated for iOS 11.

Includes the following errata fixes:
1. Iphone version:
- screen resizes properly after a phone call
- app scales properly for large format phones
- 'add-line' edit function was repaired
- total key sound is now different from CE key sound

Ratings and Reviews

4.6 out of 5

10 Ratings

10 Ratings

Great app!


I work as a restaurant manager constantly having to count register drawers and balance them maybe three times a day, also safe end of shift counting etc. Our adding machine it’s always in the office way in the back and it’s huge! No way to bring it to the front so many times so this app it’s a life saver for my day and stress levels. I’m not even going to compare it to the phone calculator. It is simply beautiful and everything I need. I very gladly paid for this after trying the free version. You won’t regret it. Thank you so much. The best.

I like it, but needs more refinements

Chris in IL

After using 10 key for a day & 1/2 pretty intensely, I'm growing to like it a lot. I'm not ready to throw out my desktop adding machine out but 10 key delivers when I'm caught away from my office.

A couple tweaks are needed: preferences for number format. Key-in defaults to a comma every 3 digits from the decimal point, but the output has no commas, and nowhere to change either formats as a default. The user needs more control over these things.

Good design and extra features


I liked the free version so much (see my review there) that I bought the paid version as a thank-you to the developer for doing such a great job of design and support.


Richard Silverman
12.6 MB
Requires iOS 9.2 or later. Compatible with iPhone, iPad, and iPod touch.
English, French, German, Italian, Spanish
Age Rating
Rated 4+
© 2010-18 Interlocken Technology


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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