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*According to the N.C.T.M.'s Principles
and Standards for School Mathematics (PSSM) document.
In the wrapping presents challenge, students have opportunities
to employ four of five process standards. They will:
- problem solve as they decide on a strategy for solving
a problem where the answer (and even the question!) is not immediately
obvious.
- reason as they think about and justify their solution,
considering all possible variables.
- communicate about their thinking by discussing it
with classmates, parents, and teachers.
- use representations (drawings, charts, words, models,
etc.) to provide a record of their efforts to understand the mathematics
of this challenge and make their understanding available to others.
About the mathematical content in this challenge:
Problems like this one may seem uncomfortably familiar to those of us
who struggled through algebra, because it seems to require solving simultaneous
equations containing three unknowns. (We don’t know how many presents
any of the three children wrapped.) Children can solve this problem, using
many different strategies. In fact teachers of older children might decide
to assign teams to try to solve it using different strategies: using manipulatives,
guess and check, looking for a pattern, making a chart or diagram, drawing
a picture, acting it out, or visualizing it. The teams could then present
their answer and their strategy to the whole class, and discuss the pros
and cons of each strategy.
About the Focal Points addressed in this challenge:
The National Council of Teachers of Mathematics (NCTM) recently released
a document titled Curriculum Focal Points for Prekindergarten
through Grade 8 Mathematics. These "Curriculum focal
points are the most important mathematical topics for each grade level.
They comprise related ideas, concepts, skills, and procedures that form
the foundation for understanding and lasting learning. They are the topics
that should be considered as the basis for decisions about curriculum
development. (For more information about these focal points, visit http://www.nctm.org/focal
points/
The Wrapping Presents challenge addresses the following recently released
NCTM focal points:
Kdg
Number and Operations: Representing, comparing, and ordering whole
numbers and joining and separating sets
Grade 1
Number and Operations and Algebra: Children develop strategies
for adding and subtracting whole numbers on the basis of their earlier
work with small numbers.
They use a variety of models, including discrete objects, length-based
models (e.g., lengths of connecting cubes), and number lines, to model
"part-whole," "adding to," "taking away from,"
and "comparing" situations to develop an understanding of the
meanings of addition and subtraction
Number and Operations and Algebra: Children solve both routine
and nonroutine problems.
Grade 3
Number and Operations: Developing an understanding of fractions
and fraction equivalence
Students develop an understanding of the meanings and uses of
fractions to represent parts of a whole, parts of a set, or points
or distances on a number line. They understand that the size of
a fractional part is relative to the size of the whole, and they use fractions
to represent numbers that are equal to, less than, or greater than 1.
They solve problems that involve comparing and ordering fractions by using
models, benchmark fractions, or common numerators or denominators. They
understand and use models, including the number line, to identify equivalent
fractions.
Grade 5
Number and Operations: Developing an understanding of and fluency
with addition and subtraction of fractions. (Harder challenge
and extension problems)
Students apply their understandings of fractions and fraction models to
represent the addition and subtraction of fractions with unlike denominators
as equivalent calculations with like denominators. They develop fluency
with standard procedures for adding and subtracting fractions and decimals.
They make reasonable estimates of fraction and decimal sums and differences.
Students add and subtract fractions and decimals to solve problems, including
problems involving measurement.
Extensions and Modifications Around the NCTM
Focal Points
Estimation of Length
Children love to wrap presents, so teachers and parents can connect this
seasonal activity to many different math concepts. Children can estimate
how much ribbon and paper they need to wrap certain presents, or they
can estimate how many bows or presents they can wrap using a spool of
ribbon or a roll of paper.
Measurement:
NCTM 2nd grade focal point-Developing an understanding of linear
measurement and facility in measuring lengths.
Children can also practice using metric or standard measurement tools
to measure out paper and ribbon.
NCTM 3rd grade focal point-Solving problems involving perimeter.
NCTM 4th grade focal point-Developing an understanding of area
and determining the areas of two dimensional shapes.
Older children can use box tops of presents to measure and compare perimeter
and area.
Geometry:
NCTM Kdg. focal point – Identify, Name
and Describe shapes and space
Younger children might want to reinforce their understanding of geometric
shapes by making square, round, triangular or rectangular cookie shapes
and naming the shapes of wrapped boxes.
NCTM 1st grade focal point – Recognize
shapes from different perspectives and orientations, describe their geometric
attributes and properties.
While tying ribbons around packages, the geometric math
terms of horizontal, vertical and diagonal can be introduced. Which method
of tying ribbon takes the most ribbon? The least ribbon?
Fractions:
NCTM 3rd grade focal point - Developing an understanding of fractions.
Since cookies are an integral part of this problem, children might try
their hand at baking several different varieties, practicing mathematics
as they halve, double, or triple recipes.
Here is the recipe for Giant Snickerdoodles.
Giant Snickerdoodles
1 cup butter or margarine, softened
1 1/2 cups plus 2 tablespoons sugar
2 eggs
2 3/4 cups all purpose flour
2 teaspoons cream of tarter
1 teaspoon baking soda
1/4 teaspoons salt
2 teaspoons cinnamon
In large mixer bowl with mixer at medium speed, cream butter or margarine,
1/1/2 C sugar and eggs until light and fluffy. In a separate bowl combine
flour, cream of tarter, baking soda, and salt. Add to cream mixture
until well blended. Refrigerate for 30 minutes.
Preheat oven to 375 degrees. Combine remaining 2 tablespoons sugar
and 2 teaspoons cinnamon in a flat open bowl. Shape dough into 2-inch
balls and roll in cinnamon-sugar. Place 3 inches apart on ungreased
cookie sheets. Bake 12 to 15 minutes until golden brown. (Snickerdoodles
will puff up at first, then flatten out to giant size during baking.)
Makes 2 dozen.
Fractions:
5th Grade focal point - Developing an understanding of and fluency with
addition and subtraction of fractions.
If aunty made 4 dozen Giant Snickerdoodle cookies, how much of
each ingredient did she use?
If she only wanted to make 1 dozen, how much of each ingredient would
she use?
Multiplication and Division:
3rd grade focal point - Developing understandings
of multiplication and division.
The average buyer will purchase 3 rolls of wrapping paper this
holiday season. If everyone in your class purchased this amount, how many
rolls of paper would this be?
It takes about 9 feet of ribbon to make a nice bow. If aunty has 12 packages
to wrap and ribbon is sold by the yard, how many yards does she need to
buy?
There are 12 cookies in a dozen. If aunty makes 4 dozen cookies while
the children wrap presents, how many cookies did she make?
A word from Aunt Mathilda about problem solving in the classroom:
Hopefully children will have opportunities to share their
different strategies with the group. Teachers should model and encourage
good listening behavior when this occurs and encourage the class to comment
positively or ask questions about the strategies. However, no one should
be allowed to make negative or comparative comments, such as "That's
a dumb way!" or "My way is better!" At no time should there
be an atmosphere which implies that there is one correct way to solve
problems – because, in fact, this is not true. The best way is the
one that make sense for the children.
P.S. from Aunty Math:
I would love to see samples of your children's work on
this problem and hear any comments you might have. Although I would not
be able to return them, I will send a personal thank you to your class
and I may mention this work in a later posting on the site. You may send
this to me care of:
Aunty Math
Dupage Children's Museum
301 N. Washington St.
Naperville, IL 60540 |