Multiply by 3367

whack · Member

Multiply by 3367

webmaster · Administrator

You can find the answer in my website under Multiplying By Specific Numbers. Here is a direct link: http://www.math-magic.com/multiply_numbers/mult_3367.htm

-- Edited by webmaster at 16:06, 2005-04-04

texasmath · Star Member

yeah, what he said!

other numbers that have shown up on older tests are:
14443 ( x 7 = 101101)

143 (x 7 = 1001)
286 (x 7 = 2002)
429 (x 7 = 3003)
572 (x 7 = 4004)
715 (x 7 = 5005)
858 (x 7 = 6006)

the last few are based on the decimal expansion for 1/7 (1/7 = .142857, round up to 143, 2/7 = .285714, round up to 286, etc.) if you always round up you'll get those patterns.

another thing to watch for would be something like
143 x 17
which you could think of as (143 x 10) + (143 x 7) = 1430 + 1001 or 2431.

so 858 x 27 = 8580 + 8580 + 6006 or 23166.

as always, take with a grain of salt.
good luck to everyone at regionals!

webmaster · Administrator

Welcome Mr. Potter! Cool pic too.

I agree with what you said. You can find some examples on each of these tricks he mentioned by visiting:

www.math-magic.com/multiply_numbers.htm

Good luck to all!