During our first investigation in our unit Factors, Multiples, and Arrays, our class created posters of the arrays for various numbers. Using these posters, students put numbers into different categories based on the kind and number of arrays they could make. The class came up with five types of numbers - odd, even, prime, composite, and square. Numbers may fall into as many as three different categories. Here is a list of noticings for each category:
Odd Numbers:
* have a 1, 3, 5, 7, or 9 in the ones place
* have only odd factors
* odd x odd = odd
Even Numbers:
* have a 2, 4, 6, 8, or 0 in the ones place
* always have a factor of 2
* each factor pair must have at least one even factor
* odd x even = even, even x odd = even, and even x even = even
Prime Numbers:
* only have 2 factors (one and itself)
* only produce one array
* 2 is the only even prime number
Composite Numbers:
* have more than two factors
* make at least 2 different arrays
* can be even or odd
Square Numbers:
* make a square array
* have an odd number of factors
* follow a pattern of odd, even, odd, even, ...
* can be made by multiplying a number by itself
ex: 1 x 1 = 1, 2 x 2 =4, 3 x 3 = 9 therefore, 1, 4, and 9 are square numbers
Thanks for posting these lesson discoveries! Davis was talking about this yesterday after school!
ReplyDeleteThe Griffin Gang
I remember even and odd numbers from 1st grade and I remember prime and composite numbers from last year but square numbers were new to me. I think I understand them but might need a little more practice. I don't always use efficient strategies when I am trying to figure out if it is a square number.
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