Categories: Cool Magic Tricks Revealed!.

Predicting the sum of Random Numbers

This is a very old but simple number prediction trick. It is not the kind of card or visual tricks where some objects will mysteriously disappear or appear out of nowhere. As usual, you may find this a tad bland after knowing the trick behind but from an audience's point of view, it still seems inexplicable. Added with a bit of showmanship and patter, your audience will still invariably be stunned!

The gist of this trick is to correctly predict the sum of random numbers that you and your friend select.

1. Take a piece of paper and ask your friend to write down a random 6-digit number between 000000 to 999999, preferably all different digits. For example: 156,289
2. Based on this number, you will write a number on another piece of paper but do not let your friend know this number. Keep this number secret for the time being.
3. Next, below the number that your friend has written in step 1 above, ask your friend to write another random 6-digit number, also between 000000 to 999999 and preferably all different. For example: 254,721
4. Then you will write another 6-digit number below the second number that your friend has written. For example: 745,278
5. Next, ask your friend to write another 6-digit number below your number. For example: 654,327
6. Following that, you will again write another 6-digit number below. For example: 345,672
7. Now you will have a total of five 6-digit numbers on the piece of paper.
• 56,289 – written by your friend
• 254,721 – written by your friend
• 745,278 – written by you
• 654,327 – written by your friend
• 345,672 – written by you
8. Sum up the five numbers and in this case you will have 2,156,287
9. Take out the piece of paper and show your friend that the secret number you’d written in step 2 is exactly 2,156,287!

So how could you have known that the result of the summation (of random numbers) would be 2,156,287?

The secret to this trick is to take note of the numbers that your friend wrote. Let’s first look at the second and third numbers that your friend wrote: 254,721 and 654,327. Whatever the numbers your friend wrote, the numbers you write after them must add up to 999,999. So…

999,999 – 254,721 (second number) = 745,278 (number you write after them) 999,999 – 654,327 (third number) = 345,672 (number you write after them)

So the sum of the last four 6-digit numbers will always be 999,999 * 2 = 1,999,998. Bearing this in mind, when your friend writes the first number, all you need to do is add 1,999,998 to your friend’s first number (156,289), and you will already be able to correctly guess the sum of all the five 6-digit numbers in step 2!

TIP: Follow the simple steps below for an easy way to add 1,999,998 to any 6-digit number

1. Place “2” in front of the 6-digit number to make it a 7-digit number. In our example above, the first number written by your friend is 156,289. So placing a “2” in front makes it: 2156,289
2. Subtract 2 from the 7-digit number: As with any number prediction trick, we recognize that it can be difficult to comprehend by just looking at numbers and words. Check out the video below for a simple illustration!

Hope you have fun with this number prediction trick!

Want to have some more tricks up your sleeves? Check out these other Cool Magic Tricks Revealed!

If you want learn more in-depth mind reading and mentalism tricks, you may be interested in this program review, on "Mastering Mentalism Effects & Magic Tricks...in Less Than 30 Days"