Add A Phone Number

[Bob Farmer]

Here is an idea that overcomes some of the problems with the classic Add-A-Number effect. Comments and criticism please.

ADD-A-PHONE-NUMBER
by Bob Farmer
July 22, 2002

INTRODUCTION
I've been thinking about better ways to do the Add-A-Number trick because aside from the potential for addition mistakes, I've always thought predicting the total of some random numbers was rather uninteresting.

So, here's the idea:

Spectator #1 writes down any phone number.

Spectator #2 writes down any phone number.

Spectator #3 crosses out either number.

Spectator #4 then calls out (say) the three numbers from the selected phone number -- the lowest, the highest and the one in the middle (or the lowest digit, the highest digit and the number formed by adding those two together).

This three (or four) digit number is then used to look up a page and entry in a phone book -- and that name and number have been predicted.

METHOD
Add-A-Number and the tossed-out deck both depend on the participating spectators being ignorant of the values their pals have picked. Thus a participant hears or sees a value which isnt one of his own, he assumes it must have been contributed by one of the others.

For this effect, any switch device can be used, but I prefer the The Forceful Notebook in FEATURE MAGIC FOR MENTALISTS by Will Dexter (Supreme 1974).

Here is the procedure:

1. Spectator #1 is asked to write down any phone number.

2. Spectator #2 then adds a second phone number below the first.

3. Before you hand the notebook to spectator #3, switch sides. He will see your two force phone numbers. Ask him to scratch one out and circle the other one.

Those two numbers have the following characteristics:

(a) Both numbers, though apparently different, are made up of the same numbers. For example, 123-456-7890 and 987-654-3210. This way, when numbers are called out:

(i) If spectator #1 doesnt hear any of his numbers, he will assume they came from spectator #2.

(ii) If spectator #2 doesnt hear any of his numbers, he will assume they came from spectator #1.

(iii) If spectator #3 is a clever bastard and has memorized the number he has chosen, he will assume the numbers called out by spectator #4 come from his number.

(b) Both numbers should use real area codes.

(c) Each number must be written in a different hand.

4. Spectator #4 is then handed the pad and asked to call out the lowest and highest digits and then add those two together to get the third or fourth number.

Alternately, if using a four-way out, you could ask for the highest digit, the lowest digit and any other digit (simply arrange the numbers so there are only 4 possibilities easily done if digits are repeated).

This approach has the advantage of no math and you can tie in the phone book angle.

[Guest]

Some interesting ideas, Bob, especially the subtleties with the digits in the numbers, etc.

That said, I don't particularly like the rest of the effect you've used it for--it's very "magicky/gimmicky" to me because of the use of the add-a-number principle to choose a number from the phone book for you to divine/predict.

If you could really do it, why wouldn't you just predict/divine the number that the first audience participant wrote down, or have her open up to any page in the phone book, drop her finger on any number, and divine that one?

Now, there is a way to come close to the former of those two effects using your ideas for the add-a-number switch itself...after all, who says that you necessarily have to receive the digits in the number in the proper order? It may be slightly risky, in that if somebody happens to remember two numbers you could get busted, but I don't think it's too risky.

[David Acer]

Hi Bob,

I've been using the Add-A-No pad to predict a cell number for years. My routine is different than what you're suggesting here, but you may want to check it out nonetheless. It's in my column in the May, 2001 Genii, under the name "Mitosis." All the best!

[Bob Farmer]

As to Andy's reservations, there seems always to be a tradeoff between directness and method. I think if you emphasized that the procedure is a method of generating a completely random phone number, then the extensive proceedings might be accepted as a plausible randomizing process.

I looked up David's effect and it's very good. A phone number is created from a random set of numbers and when the number is dialed a cell phone on stage rings -- that's gotta be a killer.

David covers the problem of spectators who can't add by using a calculator. He also describes an excellent Add-A-Number switch pad that I like better than the one I mentioned above.

Keep in mind that I'm interested not so much in the effect, but in using the A-A-N principle in a manner where math mistakes cannot happen and relating the numbers to something in the real world -- a phone number, a credit card number, a combination lock, the de-arming code on the self-destruct theatre terminator device, etc., so there's got to be other ideas possible.

It might be possible to duplicate David's effect with my method. I'll have to think about it.

One of the simplest ways would be to prepare a gaffed page in the phone book so that the selected entry is the number of your cell phone.

[Matthew Field]

As we all ponder Bob's effect, allow me to extend thanks on behalf of all Genii Forum participants for his generosity in posting it here.

Thanks, Bob, you no good . . .

Matt Field

[Bob Farmer]

Genii's resident mental case, Barrie Richardson, suggested that my idea could also be used to force words (so S1 would write a sentence, S2 would write a sentence, S3 would eliminate one and then S4 would select a word from the chosen sentence).

Obviously a progressive anagram could be easily used here so that any word selected by S4 could be divined.

This could make a lot of those expensive book tests obsolete.

[Guest]

Now that's more my style :o) It's still a bit of a compromise from just having somebody think of any word, but it's much more of a reasonable compromise than the page force. I knew I liked Barrie for a reason! Great teamwork between yourself and Barrie, Bob!