Download Study Guide for Retake Quiz – Unit 1

Study Guide for Retake Quiz – Unit 1
Prime/Composite #s (question #s 4-9)
A prime number only has 2 factors.
factor x factor = product
A composite number has 3 or more factors.
Hints Any number that has more than 1 digit and is an even # is a composite.
 Any number ending with a 5 or 0 is composite (5 as a factor).
 Many odd numbers are prime (still need to see if there are other factors).
 If a number is in both the ones and tens place that number is composite (11 as
a factor). This does not work with the number 11 though.
 If you add the two digits together and they equal 9 that # is composite (factor
of 9).
 1 is a special number. It is neither a prime nor composite number since it only
has 1 factor.
 2 is a prime number since it has only 2 factors.
Factors (question 10)
Factors are numbers that when multiplied with another number gives a product
(answer). Example: The factors of 12 – 1, 2, 3, 4, 6, 12
Multiples (question 11)
Multiples are answers (products) of two factors multiplied together. Example: The
first 5 multiples of 3 are: 3, 6, 9, 12, 15
X Strategies (question #s 12-14)
A strategy (other than a regular algorithm) should be used. The following are
examples of X strategies:
To find 14 x 5 – Skip counting 14, 28, 42, 56, 70
Repeated addition 14 + 14 + 14 + 14 + 14 = 70
Expanded Form (10 x 5) + (4 x 5) = 50 + 20 = 70
Breaking Apart (14 x 3) + (14 x 2) = 42 + 28 = 70
(7 x 5) + (7 x 5) = 35 + 35 = 70
Creating a square (question 15)
A square is when two factors are the same… 8 x 8 , 6 x 6, etc.
When given an array the task is to take that array and decide what other array can be
added to this expression to create a square. All work needs to be shown.
Example:
Given the following array, which other array would help create a square (9 x 9)?
(3 x 9) + (
x
)
Putting what is known in the equation is the first step…(3 x 9). Then another array is
needed to create a full square 9 x 9 array. 3 + ? = 9 The solution would be 6.
The 2nd step would be to plug in the new array numbers…
(3 x 9) + ( 6 x 9 )
27
+
54 =
81