trying to help my son with homework, but having trouble. sad i know. using cubes to build arrays to find factors of different numbers. for 14, factors would be 2 x 7, 7 x 2, 1 x 14, and 14 x 1. question is: can you tell when you have all of the factors for a number before you have built every possible array? help...before head explodes!
need some help with 5th grade math
- Thread starter Amy T
- Start date
Hello, Amy T!
Your problem is not clearly stated.
I don't know what "using cubes" means.
Nor do I understand "build arrays".
You say we are find the factors of a number.
Yet you have listed pairs of factors and their order makes a difference.
So what was the original question?
Here is a primitive method for finding the factors of a number.
Example: find the factors of 48.
Divide 48 by 1, 2, 3, . . .
Keep the results which "come out even".
. . \(\displaystyle \begin{array}{cccccccc} 48 \div 1 &=& 48 && \Rightarrow && 1, 48 \\ 48 \div 2 &=& 24 && \Rightarrow && 2,24 \\ 48 \div 3 &=& 16 && \Rightarrow && 3,16 \\ 48 \div 4 &=& 12 && \Rightarrow && 4,12 \\ 48 \div 5 &=& ? \\ 48 \div 6 &=& 8 && \Rightarrow && 6,8 \\ 48 \div 7 &=& ? \\ 48 \div 8 &=& 6 && \Rightarrow && 8,6 & \text{Stop!} \end{array}\)
Since (8,6) is the same factoring as (6,8), we can discard it and stop.
The last column provides the factors of 48: .\(\displaystyle 1, 2, 3, 4, 6, 8, 12, 16, 24, 48\)
Your problem is not clearly stated.
I don't know what "using cubes" means.
Nor do I understand "build arrays".
You say we are find the factors of a number.
Yet you have listed pairs of factors and their order makes a difference.
So what was the original question?
Here is a primitive method for finding the factors of a number.
Example: find the factors of 48.
Divide 48 by 1, 2, 3, . . .
Keep the results which "come out even".
. . \(\displaystyle \begin{array}{cccccccc} 48 \div 1 &=& 48 && \Rightarrow && 1, 48 \\ 48 \div 2 &=& 24 && \Rightarrow && 2,24 \\ 48 \div 3 &=& 16 && \Rightarrow && 3,16 \\ 48 \div 4 &=& 12 && \Rightarrow && 4,12 \\ 48 \div 5 &=& ? \\ 48 \div 6 &=& 8 && \Rightarrow && 6,8 \\ 48 \div 7 &=& ? \\ 48 \div 8 &=& 6 && \Rightarrow && 8,6 & \text{Stop!} \end{array}\)
Since (8,6) is the same factoring as (6,8), we can discard it and stop.
The last column provides the factors of 48: .\(\displaystyle 1, 2, 3, 4, 6, 8, 12, 16, 24, 48\)
D
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[h=2]Definition of ANTEDILUVIAN[/h]1
: of or relating to the period before the flood described in the Bible
2
a : made, evolved, or developed a long time ago <an antediluvian automobile> b : extremely primitive or outmoded <an antediluvian prejudice>
In our house these words were called SAT words - words that make you run to the dictionary.
Good thing that we have a history major - my vocubulary is improving.....:mrgreen:
: of or relating to the period before the flood described in the Bible
2
a : made, evolved, or developed a long time ago <an antediluvian automobile> b : extremely primitive or outmoded <an antediluvian prejudice>
In our house these words were called SAT words - words that make you run to the dictionary.
Good thing that we have a history major - my vocubulary is improving.....:mrgreen: