Number Sense
Math Methods
Students with good number sense
can...
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think and reason flexibly with numbers
use numbers to solve problems.
spot unreasonable answers.
understand how numbers can be taken
apart and put together in different ways.
see connections among the operations.
figure mentally.
make reasonable estimates.
(Marilyn Burns)
Students with poor number
sense...
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tend to rely on procedures rather than
reason.
do not notice when answers or
estimates are unreasonable.
have limited numerical common sense.
(Marilyn Burns)
Teaching Strategies to Build
Number Sense
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Model different methods for computing.
Ask students regularly to calculate mentally.
Have class discussions about strategies for
computing.
Make estimation an integral part of
computing.
Question students about how they reason
numerically.
Pose numerical problems that have more
than on possible answer.
Activities to build Number
Sense
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Ten Black Dots by Donald Crews
Quick Images (Investigations)
Dot Cards
Dominos
Grow and Shrink
Snap
Algebra Triangles
Literature
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Ten Black Dots by Donald Crews
Math–ter-pieces by Greg Tang
Anno’s Counting Book
Each Orange Had 8 Slices
How Many Snails
Model different ways for
computing.
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Mentally double 38. Then analyze the
method you used in order to arrive at
the answer.
Ask students regularly to
calculate mentally.
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The center region of a dartboard is
worth 100 points; the next ring is worth
50 points, the next 25 points, and the
outermost, 10 points. Betty throws six
darts and earns a score of 150. Where
might her darts have landed?
Have class discussions about
strategies for computing.
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Who else solved this in a different way?
Keep track of students’ ideas and
strategies on the board or chart.
Make estimation an integral
part of computing.
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How many times do you think a piece of yarn
or string equal to your height would
wraparound your head as a headband?
Imagine a soft drink can. Suppose you take
a piece of yarn and wrap it around the can to
measure its circumference. Do you think the
circumference is longer, shorter, or abut the
same as the height of the can? How high to
you think the circumference measure will
reach?
Question students about how
they reason numerically.
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Why do you think that?
Explain why that makes sense?
Tell more about how you reasoned?
Pose numerical problems that have
more than one possible answer.
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How could I spend exactly $1.00 by buying
two things with different prices?
How could I spend exactly $1.00 by buying
three things with different prices.
How could I spend exactly $1.00 by buying
three different things with different prices, if
one of them cost $0.39.