A large part of performance magic is in distracting your audience with otherwise useless steps and information. The core mechanic in a lot of these tricks is getting your friend to eventually subtract his given number from the equation. Once the variable is out of the way, you have full control over where the equation goes. The reason why the "Lucky Number 13" trick works so well is because multiples of 9 between 1-10 operate under in a uniquely identifiable way. In the case, each answer (e.g. 9, 18, 27 etc.) will equal to 9 if you add each digit together. Although this property is unique to multiples of 9, it makes a great trick, especially if your friend was quick to catch onto the fact that other tricks are quick to discard the original number. Adding superfluous additions and subtractions can be done as many times as you want, so long as you're ultimately able to nullify your friend's chosen variable. For instance the "End With 3" trick can be rearranged to end with any number. Once you've had some time getting used to mathematical mind tricks, you might be ready to try crafting your own. While they can become as infinitely complex as you want, it's a good thing to start out small, and slowly work your way up. For starters, use the "End With 3" as a template, and change the values of the constants to make a new equation. From there on, you'll be able to create new and inventive ways of ultimately removing the variable.  Don't forget to consistently develop your presentation as well. People want to be entertained, and the way you baffle them with your trick is going to be just as important as the trick itself!
افهم أنّ أجزاءً معينة من كل خدعة عبارة عن دخان ومرايا. ميّز الأنماط والظواهر الفريدة في الرياضيات. استوعب أن الإجابات تتوقف دائمًا على المعلومات الثابتة في المسألة. حاول أن تخترع خدعة خاصة بك.