Introduction
A journey through
elementary mathematics…twenty years later.
By: Mara Dahlberg
A lot has changed, or
perhaps been forgotten, in the past twenty years. When I originally decided to return to school
to obtain my teaching license I was fully aware that math was not my strong
point. This aspect of my education has
been a struggle since elementary school and continues to be so in college. In this blog I will be documenting my journey
through elementary math, as an adult, in hopes that I will gain some knowledge,
experience, and empathy in order to better teach my future students.
Blog 
Sets & Whole Numbers
Our first
section this week is about sets, illustrating the Big
Idea that values can be represented using any sort of ideas and
symbols, anything that can be listed or described. Sets are composed of individual values, or
elements, but are combined and looked at collectively.
When learning about sets it is
important to understand the meaning of the symbols associated with this
concept. After all, if you can’t speak
the language, you cannot comprehend its meaning.
What follows are the basics.
More information can be found at:
Some Simple Set Theory Symbols
∈ “is an element of”
∉ “is not an element of”
⊂ “is a proper subset of”
⊆ “is a subset of”
⊄ “is not a subset of”
∅ empty set; a set with no elements
∩ intersection ∪ union
The pairing
up of sets is called correspondence and sets are considered to have one-to-one correspondence if they
each have a pair.
This is an
important idea for children who are learning how to match, count, and how to
associate actual value to numbers. 
Another sub-topic of sets is subsets. A subset is a group of objects (or numbers)
found within a set or sets that are the same, a set of its own, but of which all the elements are contained in
another set.
Set B is a subset of a
set A if and only if
every object or element
of B is also an object of A.
Is
A a subset of B, where A = {1, 3, 4} and B = {1, 4, 3, 2}?
1
is in A, and 1 is in B as well. So far so good.
3
is in A and 3 is also in B.
4
is in A, and 4 is in B.
That's
all the elements of A, and every single one is in B, so we're done.
Yes,
A is a subset of B
Note
that 2 is in B, but 2 is not in A. But remember, that doesn't matter, we only
look at the elements in A.
The subset only
has elements that are found in the set.
Real World Application:
Subsets are helpful in discovering possible combinations or outcomes and
how many there are in any given situation.
Learn More
The
following are some websites with activities for elementary-age children:
k12math In depth explanations & visuals
kidzpark Printable Worksheets
onlinemathlearning Videos & Online Practice Problems
mathsisfun Easy to understand explanations
Mara Dahlberg 6/14/2013
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