dnCalc
Sebastien Raupp
Imagine... You are enjoying a lunch with friends and you suggest to perform a strange mathematical "experience".
In-app purchases in United States
Items currently visible on Apple’s public App Store page. This may not be the complete App Store Connect catalog.
Source: Apple public App Store page · Publicly visible items only · Checked Aug 5, 2026
About dnCalcStorefront description supplied by Apple.
Imagine... You are enjoying a lunch with friends and you suggest to perform a strange mathematical "experience".
You ask for several volunteers to think of a special number, a birthday, the age of their best friend...
You then ask them to multiply these numbers together, without you being able to see anything, then multiply the result by a special number that you previously wrote on a piece of paper, before the demonstration begins.
Your friends give you orally the final result of these operations.
You close your eyes and after a few seconds you reveal in the right order, the secret numbers of your friends!
dnCalc will allow you to easily produce this little miracle that you can adapt according to your wishes and to he context.
Your friends or colleagues will be asking what magical mathematical operation you mentally do to "extract" their numbers. Guaranteed to impress!
• Very easy to do. A PDF document explains in details the procedure (which you can adapt).
• Nothing to memorize.
• Up to 5 people can be involved in the demonstration.
• The spectators manipulate the calculator, you do not touch anything.
• You can do this demonstration with your eyes closed.
• No need for internet connection.
• The trick is absolutely undetectable, nothing to find.
• The effect is reproducible several times in a row.
Many other cool features :
• Force any number you need.
• Compute and peek the age of your volunteer.
• Compute and peek his zodiac signs (classic or Chinese).
• Compute and peek his birth day of week.
• Build your own forcing/peeking formulas!
*** IMPORTANT ***
If you have questions, do not ask them in the app's reviews, in order to preserve the secret.
Send an email to dnCalc@moult.org.
Thank you !
Alistair Crompton
Frequently asked questions
Quick answers based on the latest observed App Store data.
How much does dnCalc cost in United States?
The latest observed download price is Free. Open the official App Store link to confirm the current checkout price.
Does dnCalc have in-app purchases?
Apple's public page currently shows 0 purchase items in this storefront. The public list may be incomplete.