For example: 528491=5+2+8+4+9+1=29=2+9=11=1+1=2 Is 528491 a prime number? Chosen Answer: David is right on, but the process is called “Casting Out Nines”. It leads to the remainder when the number is divided by 9 and works because 9 = 10-1 and our system is base 10. Similarly, “Casting Out Elevens” can be given. It is [...]
Posts Tagged ‘number’
What is the process called when you take numbers and add them together continually to reduce them?
Posted by Eleven2 on March 2nd, 2013
How do you multiply any number by eleven mentally?
Posted by Eleven2 on April 14th, 2012
Explain and give at least 3 examples. Please more than 2 examples with a brief explanation.( Numbers bigger than 25 or 25? Please more explanations with more details and the definition or steps in how to do it. It is an oral exam so I have to give examples and i have to recite the [...]
five times the sum of a number and 2 is eleven less than eight times the number?
Posted by Eleven2 on November 25th, 2011
Chosen Answer: Let x represent the number 5(x + 2) +11 = 8x 5x + 10 + 11 = 8x 5x + 10 + 11 = 8x 5x + 21 = 8x 21 = 3x x = 7 by: ♥ɴוᴄᴏʟᴇ ɴɢᴜʏᴇɴ♥ on: 16th October 10
How many seven digit numbers ,divisible by eleven can be formed using 1,2,3,4,5,6,7?
Posted by Eleven2 on November 22nd, 2011
Chosen Answer: Nice question! An interesting test for divisibility by 11 is to alternately add and subtract the digits. The divisibility of the result by 11 determines the divisibility of the original number by 11. Effectively, you can separate the digits into two lists of length 4 and then 3, eg. [1, 3, 4, 2] [...]
Posted in Eleven2 FAQ 
Tags: alternately, answer, chosen, determines, digit, divisibility, divisible, effectively, eleven, formed, interesting, into, length, lists, many, nice, number, original, question, result, separate, seven, subtract, test, using 
1 Comment »How to solve & what’s the answer 2 this?: Four more than the quotient of a number and three is eleven?
Posted by Eleven2 on November 22nd, 2011
It’s for my math corrects,- I did really bad on this test, I got an 80%- 18.5/23 problems- and I need to do the corrections because at my school you get half the points back. I usually do well w/ variables and stuff… but not this time Chosen Answer: Let x be the unknown number. [...]
A box contains eleven balls, numbered 1,2,3….10,11,11. if 6 balls are drawn simultaneously at random, what is?
Posted by Eleven2 on November 22nd, 2011
A box contains eleven balls, numbered 1,2,3….10,11,11. if 6 balls are drawn simultaneously at random, what is the probability that the sum of the numbers on the balls drawn is odd? Chosen Answer: “eleven balls numbered 1,2,3 … 10, 11, 11″ either the numbers are 1 – 11 (no second 11) or some other number [...]
